RNA-binding protein that acts both as a transcription coactivator and pre-mRNA splicing factor (PubMed:15694343). Regulates steroid hormone receptor-mediated transcription, independently of the pre-mRNA splicing factor activity (PubMed:15694343). Highly expressed in placenta, liver, skeletal muscle, heart and kidney (PubMed:15694343). Expressed at lower levels in the colon, thymus, spleen, small intestine and lung (PubMed:15694343). Aryl sulfonamide anticancer drugs, such as indisulam (E7070) or E7820, promote ubiquitination and subsequent degradation by the DCX(DCAF15) complex (PubMed:31693891, PubMed:31686031, PubMed:31819272). Aryl sulfonamide anticancer drugs change the substrate specificity of DCAF15 by acting as a molecular glue that promotes binding between DCAF15 and weak affinity interactor RBM23 (PubMed:31686031, PubMed:31819272). Belongs to the splicing factor SR family.