The (MCL-1 + BFL-1)/BCL-2 represents the most significant linear correlation for sensitivity to ABT-737 in SCLC. SCLC cell lines with a wide range of response (resistant, intermediate, and sensitive) to ABT-737 were plotted against: (A) (MCL-1 + BFL-1)/BCL-2, (B) MCL-1/BCL-2, (C) BCL-2, and (D) (MCL-1 + BFL-1)/(BCL-2 + BCL-XL) ratios. Spearman correlation (r) and P values are shown. The Olejniczak dataset was used as extracted from the ONCOMINE database.⁴⁷