GMPPB and musculoskeletal system disorder: Functional annotation of RNF123 locus identified nine genes (SLC25A20, NDUFAF3, DAG1, HYAL1, GMPPB, TRAIP, RHOA, CACNA2D2 and IMPDH2) specific to musculoskeletal system diseases, of which CACNA2D2, NDUFAF3 and IMPDH2 enriched as druggable targets (online supplemental figure S8).