Substrate-recognition component of the DCX(DCAF15) complex, a cullin-4-RING E3 ubiquitin-protein ligase complex that mediates ubiquitination and degradation of target proteins (PubMed:16949367, PubMed:31452512). The DCX(DCAF15) complex acts as a regulator of the natural killer (NK) cells effector functions, possibly by mediating ubiquitination and degradation of cohesin subunits SMC1A and SMC3 (PubMed:31452512). May play a role in the activation of antigen-presenting cells (APC) and their interaction with NK cells (PubMed:31452512). Binding of aryl sulfonamide anticancer drugs, such as indisulam (E7070) or E7820, change the substrate specificity of the DCX(DCAF15) complex, leading to promote ubiquitination and degradation of splicing factor RBM39 (PubMed:28437394, PubMed:28302793, PubMed:31693891, PubMed:31452512). RBM39 degradation results in splicing defects and death in cancer cell lines (PubMed:28437394, PubMed:28302793, PubMed:31693891). 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 RBM39 (PubMed:31686031, PubMed:31819272). Aryl sulfonamide anticancer drugs also promote ubiquitination and degradation of RBM23 and PRPF39 (PubMed:31693891, PubMed:31626998, PubMed:31686031). Aryl sulfonamide anticancer drugs change the substrate specificity of DCAF15 by acting as a molecular glue that promotes binding between DCAF15 and weak affinity interactors, such as RBM39. Protein modification; protein ubiquitination. Component of the DCX(DCAF15) complex, also named CLR4(DCAF15) complex, composed of DCAF15, DDB1, cullin-4 (CUL4A or CUL4B), DDA1 and RBX1.