Sarcoidosis patients had significantly higher levels of OPN (patients median 217 ng/ml, 25–75% range: 149–265 vs controls median 122ng/ml, range 102–147; p<0.001), as well as CRP (patients median 2.7mg/L, 25–75% range 1.3–5.2 vs controls median 1.2mg/L, range: 0.7–3.1; p = 0.018) in comparison with healthy control subjects. Here, SPP1 is linked to sarcoidosis.