Figure 3a shows that the activity of Y2766 was almost double (411 ± 40 nmol/min/mg protein) that of Y570 (230 ± 27 nmol/min/mg protein). The crude membranes from both strains showed similar dose-dependent inhibition of ATPase activity, reaching >90% inhibition (Figure 3b) at concentrations of OM ≥ 2μg/mL. The IC50 values of Y2766 and Y570 Cdr1 ATPase activity for OM were 0.128 and 0.068, respectively. The gene discussed is CDR1; the disease is ocular melanoma.