TIMER results revealed that CDKN2A is positively correlated with CD274 (r = 0.162; p = 2.94e−04), PDCD1LG2 (r = 0.108; p = 1.6e−02), CTLA4 (r = 0.122; p = 6.64e−03), HAVCR2 (r = 0.102; p = 2.42e−02), IDO1 (r = 0.076; p = 9.26e−02), and PDCD1 (r = 0.213; p = 1.55e−06; Figures 7H–M), suggesting that CDKN2A plays a role in ICI treatment of lung adenocarcinoma. This evidence concerns the gene CTLA4 and lung adenocarcinoma.