By contrast, the lack of significant elevations or even a reduction in periostin concentrations in osteoarthritis, ankylosing spondylitis, and dermatomyositis, might reflect, in the presence of excess inflammation, a relatively lower pro-angiogenic and/or pro-fibrotic drive when compared to rheumatoid arthritis and systemic sclerosis [85–90]. Here, POSTN is linked to ankylosing spondylitis.