In vitro viability assay for XTT. Percentages of viability (means ± standard errors of the means as measured at 492 nm) relative to the viability of the control are plotted on the y axis, and increasing concentrations of caspofungin (0 to 1,024 μg/ml) in the presence of cyclosporine (0.625 μg/ml) are plotted on the x axis. ▪, C. albicans strain ATCC 90028; •, CAI4; ○, Δmkc1/Δmkc1 strain.