Co-occurring mutations have been reported in NSCLCs with EGFR ex20 ins/dup and predominantly were alternations in tumor suppressors such as TP53 (up to 65%) and RB1 (11%) and cell cycle inhibitors (cyclin-dependent kinase inhibitor 2A and 2B, 22% and 16%, respectively) (4). The gene discussed is CDKN2A; the disease is neoplasm.