PDCD1 and neoplasm: In this validation cohort, IRS-H status was associated with significantly longer PD-(L)1 rwPFS (IRS-H vs. IRS-L median 23.1 vs. 10.2 months; adjusted hazard ratio 0.52, p = 0.003) and OS (median OS 40.4 vs. 21.4 months, adjusted hazard ratio 0.49, p = 0.005) when adjusted for age, gender, line of therapy, PD-1 vs. PD-L1 therapy, and tumor type.