Similar to the findings of the study by Lu et al (20), we demonstrated that MSCs upregulated p21 and caspase-3 mRNA expression in leukemia and lymphoma cells, increasing the fraction of cells undergoing early apoptosis, and leading to cell cycle arrest at the G0/G1 phase, thus decreasing the fraction of leukemia and lymphoma cells in the S phase. Here, CASP3 is linked to leukemia.