Kuzumi A, et al. - Given that abnormal activation of macrophages is involved in the development of systemic sclerosis (SSc), authors gauged the serum interleukin (IL)-34 levels in patients with SSc. Findings suggested an association of increased serum IL-34 levels with greater frequency and severity of interstitial lung disease (ILD) in SSc patients. Researchers noted that for SSc-associated ILD, serum IL-34 levels may be a useful serological marker.