The design of venetoclax as a selective BCL-2 inhibitor followed after the development of other BCL-2 inhibitors (i.e. navitoclax) which were also shown to target BCLXL, causing concentration-dependent thrombocytopenia20.Venetoclax is currently tested in clinical pediatric cancer studies and according to preliminary results, it showed promising efficacy but was also associated with Grade 3/4 adverse events including anemia, febrile neutropenia, and thrombocytopenia, thus posing a challenge for alternative dosing regimens36. This evidence concerns the gene BCL2 and anemia (phenotype).