KRAS mutant lung cancers are highly dependent on the HER network, especially HER2 and HER3 [12,13], and KRAS mutant lung cancer patients harboring TP53 co-mutations were shown to have the best objective response rate to PD-1 blockade compared to those with STK11/LKB1 co-mutations or KRAS only mutations in the CheckMate-057 trial [29]. The gene discussed is ERBB3; the disease is lung carcinoma.