Kumanovics et al., in 135 patients with CTD-ILD (104 with systemic sclerosis, 31 with myositis), also showed that KL-6 levels were negatively correlated with FVC (r = -0.32, P < 0.001) and DLco (r = - 0.55, P < 0.001) [39]. Here, MUC1 is linked to systemic sclerosis.