SIGLEC1 and systemic sclerosis: Consistent with previous data showing an increased expression of SIGLEC-1 on the surface of CD14+ monocytes in SSc patients [18], we found evidence for an increased concentration of sSIGLEC-1 in serum samples from SSc (8.49 ng/ml, 95% CI 8.5–10.5) compared to matched healthy controls (7.07, 95% CI 6.7–8.6, P = 8.3 × 10− 3; Fig. 4b).