FAS and neoplasm: When tested FasLD164A, FasLE270A bound to Fas similar to FasLWT in ELISA (Fig. 3B) and immunoprecipitation assays (Fig. 3C and Supplementary Fig. S3D) and showed cytotoxic activity against tumor cells, Jurkat cells and T cells similar to FasLWT (Fig. 3D–G and Supplementary Fig. S3E).