CD163 and systemic sclerosis: However, environmental factors, together with individual genetical background, must be to be involved in its etiology.266 Accumulative evidence indicates that innate immunity, especially macrophage activation, plays an essential role in the pathogenesis of SSc.267 For instance, Ishikawa et al. found macrophage infiltration to skin adnexa and collagen bundles using SSc patient’s skin specimens.268 Monique Hinchcliff and Diana M Toledo et al. identified a high level of CD163-positive macrophage in patients with SSc.