CASP3 and leukemia: The lowest significant dose (LSDs) and IC50 doses of cisplatin (CSP), cyclophosphamide (CYCLO) and chlorambucil (CLB) which reduced ATP levels and increased caspase 3 activity (CASP 3) when compared to the vehicle control (P ≤ 0.05) in two lymphoid (Jurkat and CCRF-CEM) and two myeloid (THP1 and KG-1a) leukaemia cell lines; and two non-tumour control hematopoietic stem cells (CD34+ HSCs and CD133+ HSCs)