Tumor-secreted factors modulate the tumor immune microenvironment through several mechanisms, including: i) releasing immunosuppressive cytokines such as IL-2, TGF-β, IL-10, IL-35 and VEGF, which inhibit various immune cell activities (4); ii) releasing tumor-derived exosomes which contain immunosuppressive molecules, including TRAIL, Fas-L, PGE-2, etc (5); and iii) recruiting regulatory immune cells such as regulatory-T cells, tumor associated macrophages, and myeloid-derived suppressor cells to the tumor site (6). The gene discussed is FASLG; the disease is neoplasm.