CD274 and neoplasm: Notably, while broad transcriptional changes were noted early (day 5; Fig. 4B; Supplementary Table S4), anti-ICOS mAb (mIgG1 or rIgG2b) treatment significantly induced expression of both PD-1 (PDCD1) and PD-L1 (CD274) in tumor tissue on day 7 (Fig. 4C; Supplementary Fig. S10A; Supplementary Table S4).