MBTPS1 and spondyloarthropathy: In this line, recently it has been shown that SphKs/S1P axis is involved in SA at multiple levels33, indeed in SA patients this axis may promote IL-17 production and directly regulate metabolic pathways determining the mineralization capacity of osteoblasts and chondrocytes in SA, suggesting that this axis may be a peculiar therapeutic target in spondyloarthritis.