Other biomarkers associated with SSc-ILD and severity of pulmonary involvement are C-C motif chemokine ligand 2 (CCL-2), chitinase 3 like 1 (YKL-40), MMP-7 and MMP-12, connective tissue growth factor (CTGF), and IL-6 [120]. This evidence concerns the gene CHI3L1 and interstitial lung disease.