Interestingly, in the context of glioblastoma, navitoclax has been the more promising substance, suggesting that modulation of Bcl-xL is needed for therapeutic efficacy (Hlavac et al., 2019; Nguyen et al., 2019), unfortunately navitoclax is also associated with serious, but manageable side effects, such as thrombocytopenia and neutropenia, severely limiting its therapeutic value (Wilson et al., 2010; Kuter, 2015). Here, BCL2L1 is linked to glioblastoma.