ATP6AP2 and testicular germ cell tumor: Consistently, we have compared the levels of ATP6AP2 transcripts in tumor tissues of different cancers and corresponding matched normal tissues, based on the data provided in The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) databases, and found that obviously higher ATP6AP2 expression widely exists in various cancers, especially in the lymphoid neoplasm diffuse large B-cell Lymphoma (DLBC), kidney renal clear cell carcinoma (KIRC), pancreatic adenocarcinoma (PAAD), stomach adenocarcinoma (STAD), testicular germ cell tumors (TGCT) and thymoma (THYM) (Fig. 1).