CDKN2A and cancer: Two‐hit inactivation of CDKN2A/2B was frequently found in KRAS‐mutant LUAD in The Cancer Genome Atlas (TCGA) database, and loss of CDKN2A/B fostered cellular proliferation, cancer cell differentiation, and metastatic behavior in genetically engineered mouse models of KRAS‐mutant lung tumorigenesis [14].