The ability of PhenDC3 to enhance the binding of RBM25 to rG4 in BCL-x pre-mRNA, and thereby to promote the alternative pro-apoptotic Bcl-xS isoform and apoptosis indicates that favouring the interaction between RBM25 and the GQ-2 rG4 in BCL-x pre-mRNA represents a relevant intervention point to re-sensitize cancer cells to chemotherapy. Here, BCL2L1 is linked to cancer.