Dysregulation of ABC protein expression has been observed in both solid and diffuse tumors, with high levels of expression that are often reported in drug-naive tumors, even when the tissue of origin exhibits little or no expression of the corresponding gene10; for example, the overexpression of ATP binding cassette subfamily C member 1 (ABCC1) (MRP-1) in astrocytic tumors compared to the low or undetectable expression in normal astrocytes11. The gene discussed is ABCC1; the disease is astrocytic tumor.