There have been previous reports of strategies that promote shifts in Bcl-X splicing, including the use of inhibitors of SR protein phosphorylation (Moore et al., 2010; Shkreta et al., 2017) and splice switching oligonucleotides (SSOs) that block the XL 5′ ss and thereby reduce the overall cell viability of a variety of cancer cell lines (Mercatante et al., 2002; Bauman et al., 2010; Li et al., 2016). This evidence concerns the gene BCL2L1 and cancer.