CEACAM5 and leukemia: To test the cytolytic activity of CSPG4-CAR T cells, CEA control T cell, and mock T cells toward KOPN8 leukemia cells, we first performed a 4 h degranulation assay analyzing CD107a upregulation on CD8+ T cells after co-incubation with T2.A1, KOPN8, and A375M cells.