These include downregulation of major histocompatibility complex (MHC) class I or class II molecules, loss of immune costimulatory molecules and gain of co-inhibitory signals, defects in antigen-processing machinery (APM), as well as the presentation of tumor-associated antigens (TAA), and downregulation of TAA.148 In addition, overexpression of immunosuppressive molecules, including TGF-β, PGE2, IL-6, IL-10, adenosine, and/or the expression of Fas ligand (FasL), lead to the death of TILs148 and help cancer cell to escape immune recognition. The gene discussed is FASLG; the disease is cancer.