Fig. 3. Response surfaces for C0–CDDP (A and D), CDDP–GSH (B and E) and C0–GSH (C and F) for CCRF-CEM-wt (left) and CCRF-CEM-res (right) cell lines. The experimental points (■) are superimposed to the surfaces. The contour plots of cytotoxicity iso-values are shown in the bottom planes.