CD33 and chronic myelogenous leukemia, BCR-ABL1 positive: The leukocyte mRNA expression of OATP1B1, OATP1B3, OCT1, NTCP, and ABCB1 of these CML patients was also measured by quantitative real-time PCR (Figure 4A) and correlated with the dye uptake behavior of the three cell fractions CD33−/CD34−, CD33+/CD34−, and CD33+/CD34+ after incubation with DY-630 and DY-635.