TNFSF15 and musculoskeletal system disorder: Members of the tumor necrosis factor superfamily (TNFSF) such as LIGHT (TNFSF14), B lymphocyte stimulator (BLyS; TNFSF13B), a proliferation-inducing ligand (APRIL; TNFSF13A) and TNF-like protein 1A (TL1A; TNFSF15) are elevated in the serum and/or synovial fluid of RA patients, potentially contributing to the bone pathology associated with the musculoskeletal disease [12], [13], [14].