HNRNPL and neoplasm: Other splicing factors have been found to regulate back-splicing in different biological settings: RBM20 promotes the biogenesis of circRNAs by regulating the exclusion of specific exons (77) and heterogeneous nuclear ribonucleoprotein L (HNRNPL) regulates back-splicing and promotes the biogenesis of circRNAs and tumor growth in prostate cancer (76).