Other mechanisms of resistance observed in CLL patients treated with venetoclax included early outgrowth of clones with complex karyotype, mutations in BTG1, aberrations of CDKN2A/B (21), and BCL2 mutation Gly101Val alone or associated with other additional acquired BCL2 resistance mutations, as recently reported (22, 23). Here, BTG1 is linked to B-cell chronic lymphocytic leukemia.