Especially under inflammatory conditions, a question arises about whether the activated S1P-S1PR1 signaling would trigger osteogenesis in osteoblast-precursors, and it could be proposed that this signaling plays a role in the pathogenesis of inflammation-related bone sclerosis lesions, such as bone spurs in arthritis or sequestrum in osteomyelitis. The gene discussed is MBTPS1; the disease is arthritic joint disease.