Consistently, LIGHT is a pro-osteoclastogenic cytokine [21] and high levels have been demonstrated in erosive bone disease, firstly in rheumatoid arthritis [48] and then by bone metastatic non-small cell lung cancer (NSCLC), in osteolytic multiple myeloma, alkaptonuria, chronic kidney disease (CKD), hemodialysis patients, and post-menopausal osteoporosis [19,21,22,23,24,25]. Here, TNFSF14 is linked to alkaptonuria.