In drug-resistant SCLC cells, epithelial splicing regulatory protein 1 (ESRP1) expression was significantly downregulated, which increased the proportion of full-length CARM1 (CARM1FL) by regulating the selective splicing of coactivator associated arginine methyltransferase 1 (CARM1). The gene discussed is CARM1; the disease is small cell lung carcinoma.