CDKN2A and glioblastoma: Moreover, while some tumors, such as GBM, MESO, and SARC, have experienced “deep deletion” as approximately the only form of genetic alteration, others, including HNSC, PAAD, and LUSC, experienced “mutation” in addition to “deep alteration” as the major forms of CDKN2A genetic alterations (Figure 5A).