Chemotherapy induced BC cells to secrete multiple EV miRNAs, including miR-9-5p, miR-195-5p, and miR-203a-3p, which simultaneously targeted the transcriptional factor one cut homeobox 2 (ONECUT2), leading to the induction of CSC phenotypes and expression of stemness-associated genes, including NOTCH1, SOX9, NANOG, OCT4, and SOX2. Inhibition of these miRNAs or restoration of ONECUT2 expression abolished the CSC-stimulating effect of EVs from chemotherapy-treated cancer cells. This evidence concerns the gene ONECUT2 and cancer.