This functional contradiction of PELI1 may be caused by the essential difference between adenocarcinoma, osteosarcoma and squamous cell carcinomas, which also suggests that PELI1 may functions in a context‐dependent manner as a tumor suppressor in squamous cell carcinomas, whereas it functions as a oncoprotein in adenocarcinoma. The gene discussed is PELI1; the disease is osteosarcoma.