Moreover, we discovered that KRT19 regulates CSC reprogramming and drug sensitivity in breast cancer and cancer stem cell-like cells, through mediating stemness (NANOG, OCT4, KLF4, and SOX2) and drug-resistant (ALDH1, ABCG2, ABCC1, and ABCB1) marker expression. Here, ABCG2 is linked to breast cancer.