CASP3 and neoplasm: We monitored: (1) interferon-dependent gene expression using ISRE and GAS luciferase reporters; (2) MHC-I/PD-L1 surface expression ratios; and (3) tumor cell killing by HLA-matched peripheral blood mononuclear cells (PBMCs), measured via caspase-3/7 activity (Fig. 2a).