IncreasingCA XII levels at the plasma membrane of P-gp positive cancer cellswere found during the acquisition of chemoresistance.31 P-gp-mediated chemoresistance is reversed by CA XII inhibitors.32 The 3,4,5-trimethoxybenzoyl moiety of compound 9 was required for modulating P-gp levels.33 The gene discussed is PGP; the disease is cancer.