PCNA and acute myeloid leukemia: Quantification analysis of immunofluorescent staining showed that the percentage of tubules with one layer of PCNA-positive staining significantly increased in the AML group 2 weeks post treatment compared to control; CT (Figure 6B), whereas a significant decrease in the percentage of tubules with one layer of PCNA-positive staining was detected in the CYT-treated group 2 weeks post treatment compared to control; CT (Figure 6B).