In OS, the GEIPA2 database showed (Fig. 2A, B) that in the vast majority of cases, patients with kidney chromophobe (KICH P = 0.016 HR = 8.6), brain lower grade glioma (LGG P = 0.00096 HR = 1.9), testicular germ cell tumors (TGCT P = 0.045, HR = 6e + 08), and uveal melanoma (UVM P = 0.038 HR = 2.6) with high levels of STAT3 expression had a significantly worse median survival time than those with low expression. Here, STAT3 is linked to testicular germ cell tumor.