Pan-cancer analysis (N = 1904) revealed that patients harboring ARID1A mutation (N = 291) had a longer OS than those with a wild-type gene after ICI administration (28.0 months versus 18.0 months, P = 0.0052), as displayed in Fig. 1A. ARID1A mutation was found to be related to the genomic instability of malignancy represented by a higher TMB both in pancancer patients (18.14/Mb versus 5.27/Mb, P < 0.0001, Fig. 1B) and LUAD patients (13.03/Mb versus 7.14/Mb, P = 0.0071, Fig. 1C). This evidence concerns the gene ARID1A and cancer.