Despite the evidence of the direct and indirect pro-osteoclastogenetic properties of IL-17 and its role in systemic and focal bone loss in RA and SpA (discussed above), surprisingly, several studies report IL-17 as a promoter of osteoblastogenesis, leading to higher bone formation, probably via a JAK2/STAT3 pathway [231]. This evidence concerns the gene IL17A and rheumatoid arthritis.