Recently, the breast cancer-resistant protein (BCRP), the equivalent of mitoxantrone-resistant protein (MXR) or placental ABC transporter (ABCP), was described in AML.
Additionally, but more controversial, expression of the ABC transporter multidrug resistance protein (MRP) and the vault-transporter lung resistance protein (LRP) have been correlated with outcome in AML.
A median fluorescence intensity ratio (MFIR) which measures the efflux of mitoxantrone (an ATP Binding Cassette (ABC) transporter substrate) with and without ABC transporter inhibition correlates with expression of MDR1 and BCRP in acute myeloid leukemia (AML) blasts.