TNFRSF9 and neoplasm: Therefore, to establish a protocol for simultaneous in vitro detection of CD137 upregulation and production of TNF and IFNγ, we initially tested how the protein transport inhibitors Brefeldin A (BFA) and Monensin (MN) affected the expression of CD137 in TILs following tumor-antigen specific activation (Figure 1 and Supplementary Figure 4).