The WB analysis demonstrated that the phosphorylation of p-GSK3β (Tyr216) and p-Src levels were increased significantly upon the knockdown or overexpression of KRT19 in MDA-MB231 or KU-CSLC cells, while the expression of p-AKT, p-GSK3β (Ser9), p-ERK, and p-JNK was unchanged (Figure 6C,D), which is suggested that KRT19 could regulate the cancer stem cell reprogramming by partially modulating the phosphorylation of GSK3β (Tyr216) and Src in breast cancer or cancer stem cells. This evidence concerns the gene MAPK8 and cancer.