MCL1 and cancer: There are many examples of MCL-1 inhibition, typically via siRNA-mediated knockdown, sensitizing cancer cell lines to killing by ABT-737.16, 17, 18, 19, 52 We therefore tested the combination of navitoclax and A-1210477 in a panel of cancer cell lines known to depend on BCL-XL and MCL-1 for survival, for example, the gastric cancer cell line EJ-1.19, 52 As expected, navitoclax had little or no effect on these cell lines up to 3–5 μM, concentrations that will typically kill cells dependent on BCL-2 and/or BCL-XL alone (Figure 6).