Building on earlier studies that explored the heterogeneous role of PD-L1 in CRC [28, 32, 49], we began by analyzing gene expression correlations between PTGS2, CD274, and CD8A across three independent datasets: GSE39582, TCGA-COAD, and E-MTAB-12,862. The gene discussed is PTGS2; the disease is colorectal carcinoma.