For example, Bcl-X can produce the anti-apoptotic long splicing isoform Bcl-XL, as well as the pro-apoptotic short isoform Bcl-XS, with RBM4 and SRSF1 modulating Bcl-X splicing, thereby influencing lung cancer development 23. The gene discussed is BCL2L1; the disease is lung carcinoma.