Therefore, our findings indicate that following treatment with chemotherapeutic drugs, Rack1 overexpression abrogated reduction of PKC kinase activity and thus decreased the FEM1b-Apaf1-caspase 3 apoptotic signaling, finally leading to reduction of apoptosis and development of chemoresistance in T-ALL derived cell line. The gene discussed is CASP3; the disease is acute lymphoblastic leukemia.