BCL2L1 and plasma cell myeloma: For example, venetoclax (ABT-199); a selective Bcl-2 inibitor which is used in the treatment of multiple myeloma has been shown to be effective in the setting of high Bcl-2 expression with concomittant low Bcl-XL expression and cells which co-express Bcl-2 and Bcl-XL to similar levels are resistant to venetoclax and require additional treatment with a Bcl-XL inhibitor (Punnoose et al., 2016).