HIPK2 and osteosarcoma: Both CDH1 and TGFB1 are the targets of CtBP1 in other types of tumor cells; however, we cannot conclude that they are controlled by CtBP1 in the tumorigenesis of osteosarcoma because many transcription factors can regulate the expression of CDH1 and TGFB1. More efforts are needed to study the influences of HIPK2 overexpression, especially its effects on the EMT and metastasis.