Clinical testing of ABT263 was initially associated with thrombocytopenia in patients, due to the reliance of platelets on Bcl‐XL for survival (Mason et al., 2007), but changes in ABT263 dosing to include an initial ramping period have overcome the acute thrombocytopenia (Roberts et al., 2015). The gene discussed is BCL2L1; the disease is Thrombocytopenia.