We found that the correlation results were not gene-specific but tumor type-specific: ITIH1 expression did not show correlations with specific checkpoint genes across pan-cancers; however, strong correlations were found between ITIH1 and most of the checkpoint genes in specific cancer types, such as HNSC, LGG, LIHC, LUSC, mesothelioma (MESO), THYM, and uterine corpus endometrial carcinoma (UCEC) (Supplementary Figure 12). Here, ITIH1 is linked to uterine corpus endometrial carcinoma.