Eight cancers were found to express GZMK less than the comparable normal tissues, such as BLCA, COAD, KICH, LIHC, LUSC, READ, THCA, and UCEC; sixteen tumors had higher TREM2 expression than the corresponding normal tissues, such as BLCA, BRCA, CESC, CHOL, COAD, ESCA, GBM, HNSC, KICH, KIRC, KIRP, LIHC, PRAD, STAD, THCA, and UCEC; and six cancers expressed more OR4D10 than the matching normal tissues, including BRCA, KICH, KIRC, LUAD, STAD, and THCA (Figure 1A–C). Here, TREM2 is linked to cancer.