CDKN2A and glioblastoma: Regarding patient stratification, co-deletion with methylthioadenosine phosphorylase (MTAP) and the tumor suppressor gene CDKN2A (p16) are observed in 40% of glioblastomas, 25% of melanomas and pancreatic adenocarcinomas, and 15% of non-small cell lung carcinomas (82).