ISG15 expression was positively correlated with cancer-associated fibroblast (CAF) infiltration in COAD (colon adenocarcinoma), LGG, and THCA, while showing negative correlations in several other cancers such as BRCA, CESC, HNSC (HPV-), and mesothelioma (MESO) (see Supplementary Fig. S3). Here, ISG15 is linked to cancer.