In conclusion, knocking down the expression of cyclin A2 by siRNA delivered by SWNTs suppresses apoptosis and erythroid differentiation, and promotes megakaryocytic and monocyte-macrophage differentiation in human chronic myelogenous leukaemia K562 cells upon administration with DOX. This evidence concerns the gene CCNA2 and chronic myelogenous leukemia, BCR-ABL1 positive.