SIGLEC15 and cancer: Also, SIGLEC11 mRNA expression was down-regulated in 19 out of 24 cancer types (except GBM, HNSC, THCA, and sarcoma [SARC], prostate adenocarcinoma [PRAD]), and SIGLEC15 was up-regulated in 18 out of 24 cancer types (except BRCA, KIRC, LUSC, PRAD, thymoma [THYM], and skin cutaneous melanoma [SKCM]) (Figure 3).