RET and non-small cell lung carcinoma: In contrast, the top 10 genes that are altered among RET fusion-negative NSCLC patients are TP53 (68%), KRAS (31%), CDKN2A (29%), CDKN2B (17%), STK11 (16%), EGFR (16%), MTAP (13%), PIK3CA (10%), RB1 (8%), and MYC (8%).