PRMT4 is regulated by RBM5, which induces exon 9 skipping and nonsense-mediated decay [205], while ESRP1 modulates splicing to generate PRMT4-FL and PRMT4-ΔE15 isoforms that suppress the TGF-β/Smad pathway and reverse chemotherapy resistance in small cell lung cancer [206]. The gene discussed is CARM1; the disease is small cell lung carcinoma.