KRT19 and breast cancer: Recent studies indicate that KRT19 can regulate cancer properties by modulating signaling pathway cascades such as the EGR1/PTEN/AKT, Wnt/β-catenin/Notch, and other pathways [13,14], with knockdown of KRT19 promoting breast cancer cell proliferation, migration, and sphere formation through NUMB-dependent crosstalk in the Wnt/Notch signaling pathway [13] and activation of AKT signaling [14].