In our study, relative to values in the basal group, Abcb1a/b mRNA expression was ~ 3-fold higher and ABCB1 protein levels were ~ 4-fold higher in the intermediate tumor group, while Abcb1a/b mRNA expression was ~ 521-fold higher and ABCB1 protein levels were ~ 13-fold higher in the high ABCB1–expressing group. The gene discussed is ABCB1; the disease is neoplasm.