ERCC4 and cancer: To further explore the potential mechanism underlying the association between MMR/DDR mutations and the therapeutic efficacy of ICI, we performed univariate Cox regression (Supplementary Table S5) in the MSK-IMPACT cohort and found that ATM, BRCA2, ERCC4, NBN, POLE, RAD50, and TP53 mutations, cancer types, MMR status, and TMB were associated with OS (all P < 0.05).