S100A4 and psoriasis: In contrast, S100A4 levels did not correlate with disease activity as determined by BASDAI or CRP levels (r = − 0.197, p = 0.139; r = − 0.219, p = 0.099; respectively) and did not differ between patients with or without peripheral joint involvement or other clinical manifestations such as psoriasis, inflammatory bowel disease or presence of uveitis (Additional file 1).