The KILR 4T1 Cell Pool is a stable, engineered cell pool, which closely reflects the heterogeneous native protein expression of tumor environments, used to measure direct cell death mediated by immunooncology treatmnets (e.g. checkpoint modulators, bispecifics, CAR-T, etc.) via Antibody Dependent Cell-mediated Cytotoxicity (ADCC), Complement Dependent Cytotoxicity (CDC), and Antibody Dependent Cell Phagocytosis (ADCP).This product uses EFC technology. The cell pool is a heterogeneous population of 4T1 cells that overexpress a ProLabel-tagged housekeeping gene. Upon effector cells-mediated cell lysis, ProLabel is released to the media, where EA in the detection kit produces and EFC signal proportional to the level of ProLabel released. This allows for calculation of percent lysis of the KILR cell pool. This stable cell pool is provided as two vials of cryopreserved cells.