1. Siegel RL, Miller KD, Fuchs HE, Jemal A. Cancer statistics, 2021. CA Cancer J Clin. 2021;71:7-33.
2. Clarke MF, Dick JE, Dirks PB, et al. Cancer stem cells—perspectives on current status and future directions: AACR workshop on can- cer stem cells. Cancer Res. 2006;66(19):9339-9344. http://dx.doi. org/10.1158/0008-5472.can-06-3126
3. Bonnet D, Dick JE. Human acute myeloid leukemia is organized as a hierarchy that originates from a primitive hematopoietic cell. Nat Med. 1997;3:730-737.
4. Al-Haji M, Wicha MS, Benito-Hernandez A, Morrison SJ, Clarke MF. Prospective identification of tumorigenic breast cancer cells. Proc Natl Acad Sci USA. 2003;100:3983-3988. https://www.pnas.org/ content/100/7/3983.long
5. Singh SK, Clarke ID, Terasaki M, et al. Identification of a cancer stem cell in human brain tumors. Cancer Res. 2003;63(18):5821-5828.
6. Takaishi S, Okumura T, Tu S, et al. Identification of gastric can- cer stem cells using the cell surface marker CD44. Stem Cells. 2009;27(5):1006-1020.
7. O’Brien CA, Pollett A, Gallinger S, Dick JE. A human colon cancer cell capable of initiating tumour growth in immunodeficient mice. Nature. 2007;445:106-110.
8. Ricci-Vitiani L, Lombardi DG, Pilozzi E, et al. Identification and expansion of human colon-cancer-initiating cells. Nature. 2007;445(7123):111-115.
9. Prince ME, Sivanandan R, Kaczorowski A, et al. Identification of a subpopulation of cells with cancer stem cell properties in head and neck squamous cell carcinoma. Proc Natl Acad Sci USA. 2007;104(3):973-978.
10. Eramo A, Lotti F, Sette G, et al. Identification and expansion of the tumorigenic lung cancer stem cell population. Cell Death Differ. 2008;15(3):504-514.
11. Ma S, Chan KW, Hu L, et al. Identification and characterization of tumorigenic liver cancer stem/progenitor cells. Gastroenterology. 2007;132(7):2542-2556.
12. Yang ZF, Ho DW, Ng MN, et al. Significance of CD90+ cancer stem cells in human liver cancer. Cancer Cell. 2008;13(2):153-166. http:// dx.doi.org/10.1016/j.ccr.2008.01.013
13. Collins AT, Berry PA, Hyde C, Stower MJ, Maitland NJ. Prospective identification of tumorigenic prostate cancer stem cells. Cancer Res. 2005;65(23):10946-10951. http://dx.doi.org/10.1158/0008-5472. can-05-2018
14. Chan KS, Espinosa I, Chao M, et al. Identification, molecular characteriza- tion, clinical prognosis, and therapeutic targeting of human bladder tumor- initiating cells. Proc Natl Acad Sci USA. 2009;106(33):14016-14021.
15. Li C, Heidt DG, Dalerba P, et al. Identification of pancreatic cancer stem cells. Cancer Res. 2007;67(3):1030-1037.
16. Hermann PC, Huber SL, Herrler T, et al. Distinct populations of can- cer stem cells determine tumor growth and metastatic activity in human pancreatic cancer. Cell Stem Cell. 2007;1(3):313-323.
17. Okusaka T, Furuse J. Recent advances in chemotherapy for pancre- atic cancer: evidence from Japan and recommendations in guide- lines. J Gastroenterol. 2020;55(4):369-382.
18. Shah AN, Summy JM, Zhang J, Park SI, Parikh NU, Gallick GE. Development and characterization of gemcitabine-resistant pan- creatic tumor cells. Ann Surg Oncol. 2007;14:3629-3637.
19. Dembinski JL, Krauss S. Characterization and functional analysis of a slow cycling stem cell-like subpopulation in pancreas adenocarci- noma. Clin Exp Metastasis. 2009;26:611-623.
20. Mani SA, Guo W, Liao MJ, et al. The epithelial-mesenchymal transition generates cells with properties of stem cells. Cell. 2008;133(4):704-715.
21. Hwang WL, Yang MH, Tsai ML, et al. SNAIL regulates interleukin-8 expression, stem cell-like activity, and tumorigenicity of human col- orectal carcinoma cells. Gastroenterology. 2011;141(1):279-291.
22. Liu CW, Li CH, Peng YJ, et al. Snail regulates Nanog status during the epithelial-mesenchymal transition via the Smad1/Akt/GSK3β signaling pathway in non-small-cell lung cancer. Oncotarget. 2014;5(11):3880- 3894. http://dx.doi.org/10.18632/oncotarget.2006
23. Sun Y, Song GD, Sun N, Chen JQ, Yang SS. Slug overexpression in- duces stemness and promotes hepatocellular carcinoma cell inva- sion and metastasis. Oncol Lett. 2014;7(6):1936-1940.
24. Chen C, Wei Y, Hummel M, et al. Evidence for epithelial- mesenchymal transition in cancer stem cells of head and neck squa- mous cell carcinoma. PLoS ONE. 2011;6(1):e16466.
25. Maruno T, Fukuda A, Goto N, et al. Visualization of stem cell activity in pancreatic cancer expansion by direct lineage tracing with live imaging. Elife. 2021;10:e55117.
26. Recouvreux MMR, Galenkamp KMO, et al. Glutamine depletion regulates Slug to promote EMT and metastasis in pancreatic cancer. J Exp Med. 2020;217(9):e20200388.
27. Miyoshi H, Stappenbeck TS. In vitro expansion and genetic mod- ification of gastrointestinal stem cells as organoids. Nat Protoc. 2013;8:2471-2482.
28. Dontu G, Abdallah WM, Foley JM, et al. In vitro propagation and transcriptional profiling of human mammary stem/ progenitor cells. Genes Dev. 2003;17(10):1253-1270. http://genesdev.cshlp.org/ content/17/10/1253.long
29. Singh SK, Hawkins C, Clarke ID, et al. Identification of human brain tumour initiating cells. Nature. 2004;432(7015):396-401.
30. Tsuda M, Fukuda A, Kawai M, Araki O, Seno H. The role of the SWI/ SNF chromatin remodeling complex in pancreatic ductal adenocar- cinoma. Cancer Sci. 2021;112(2):490-497.
31. Rodriguez-Aznar E, Wiesmuller L, Sainz B Jr, Hermann PC. EMT and stemness-key players in pancreatic cancer stem cells. Cancers (Basel). 2019;11(8):1136.
32. Chen R, Masuo K, Yogo A, et al. SNAIL regulates gastric carcinogenesis through CCN3 and NEFL. Carcinogenesis. 2021;42(2):190-201.
33. Zheng X, Carstens JL, Kim J, et al. Epithelial-to-mesenchymal tran- sition is dispensable for metastasis but induces chemoresistance in pancreatic cancer. Nature. 2015;527(7579):525-530.
34. Hotz B, Arndt M, Dullat S, Bhargava S, Buhr HJ, Hotz HG. Epithelial to mesenchymal transition: expression of the regula- tors snail, slug, and twist in pancreatic cancer. Clin Cancer Res. 2007;13(16):4769-4776.
35. Nieto MA. The snail superfamily of zinc-finger transcription factors. Nat Rev Mol Cell Biol. 2002;3:155-166.
36. Seino T, Kawasaki S, Shimokawa M, et al. Human pancreatic tumor organoids reveal loss of stem cell niche factor dependence during disease progression. Cell Stem Cell. 2018;22(3):454-467.
37. Date S, Sato T. Mini-gut organoids: reconstitution of the stem cell niche. Annu Rev Cell Dev Biol. 2015;31:269-289.
38. Boj SF, Hwang CI, Baker LA, et al. Organoid models of human and mouse ductal pancreatic cancer. Cell. 2015;160(1–2):324-338.
39. Hwa V, Oh Y, Rosenfeld RG. The insulin-like growth factor-binding protein (IGFBP) superfamily. Endocr Rev. 1999;20(6):761-787.
40. Russo VC, Azar WJ, Yau SW, Sabin MA, Werther GA. IGFBP-2: The dark horse in metabolism and cancer. Cytokine Growth Factor Rev. 2015;26(3):329-346.
41. Fukushima T, Tezuka T, Shimomura T, Nakano S, Kataoka H. Silencing of insulin-like growth factor-binding protein-2 in human glioblas- toma cells reduces both invasiveness and expression of progression- associated gene CD24. J Biol Chem. 2007;282(25):18634-18644.
42. Lee EJ, Mircean C, Shmulevich I, et al. Insulin-like growth factor binding protein 2 promotes ovarian cancer cell invasion. Mol Cancer. 2005;4(1):7.
43. So AI, Levitt RJ, Eigl B, et al. Insulin-like growth factor binding pro- tein-2 is a novel therapeutic target associated with breast cancer. Clin Cancer Res. 2008;14(21):6944-6954.
44. Liu H, Li L, Chen H, et al. Silencing IGFBP-2 decreases pancreatic cancer metastasis and enhances chemotherapeutic sensitivity. Oncotarget. 2017;8(37):61674-61686.
45. Gao S, Sun Y, Zhang X, et al. IGFBP2 activates the NF-kappaB pathway to drive epithelial-mesenchymal transition and invasive character in pan- creatic ductal adenocarcinoma. Cancer Res. 2016;76(22):6543-6554.
46. Li T, Forbes ME, Fuller GN, et al. IGFBP2: integrative hub of developmental and oncogenic signaling network. Oncogene. 2020;39(11):2243-2257.