METTL3 and testicular germ cell tumor: For example, downregulation of METTL3 in testicular germ cell tumors (TGCT) tissue is positively correlated with levels of tumor-infiltrating CD8 + T cells, CD4 + T cells, and NK cells [184], whereas the increased METTL3 level in CRC is negatively related with infiltration of CD8 + T cells and secretion of IFN-γ, CXCL9, and CXCL10 [135].