BCL2L1 and neoplasm: Consistent with a requirement for BCL-xL inhibition to achieve synergistic anti-tumor effects in combination with taxanes in tumors of epithelial origin [12–14], the combination of Abraxane® and ABT-199, generally elicited only a slightly elevated response compared to either drug alone and βs(r) was not significantly different from 0 for the combination of Abraxane® and ABT-199 at any of the radial distances tested (Fig 4).