Combination of ABT-737 and chloroquine results in increased induction of apoptosis in SCLC cell lines. Cells were treated at the doses listed in Figure 1 for ABT-737 and chloroquine or the combination for 72 hrs, and then assayed using the Caspase-Glo 3/7 assay. Luminescence is directly proportional to the amount of caspase-3 activation. Commercially available cell lines are shown in A and cell lines derived from patient xenografts are shown in B. Error bars: SD; n = 4.