PBK and skin squamous cell carcinoma: It was observed that the autophagy level decreased after knocking out the expression of TOPK in cSCC cells but increased after upregulating the expression of TOPK; on the basis of upregulating TOPK, the autophagy level of cells was significantly inhibited after adding autophagy inhibitor 3-MA, and the migration and invasion ability of cells also decreased; this suggests that TOPK could activate autophagy and promote the metastasis of cSCC cells, which is in line with the report of Yoshihara et al. [21] who found that autophagy is activated during the disease progression of cSCC patients.