It has been shown that P388 leukemia cells synchronized in S and G2/M phases were more sensitive to DOX than cells in G1 phase [16], however, our study showed accumulation of Ehrlich cells in G1 phase by RSVL,DOX and their combination with significant decrease in number of cells in S phase which may be due inhibition of the enzyme used for DNA replication [17-19] or increase expression of positive G1/S regulators, such as cyclin D1 and cyclin E which are responsible for S phase entry [20,21]. This evidence concerns the gene CCNE1 and leukemia.