CDKN2A and central nervous system cancer: Ping et al. (2014) showed that the glioma pathway was affected by 12 different genes (including EGFR, PDGFRA, CAMK2B, AKT1, CDK4, MDM2, NRAS, PIK3CA, TGFA, SHC4, CDKN2A, and PDGFA) with significant patterns of mutual exclusivity.