IGFBP1 and systemic sclerosis: Serum molar ratio of total IGF-1/IGFBP-1 was significantly lower in SSc-no ILD patients compared to HS (p < 0.001), and total IGF-1/IGFBP-2 was significantly lower in SSc-no ILD and SSc-ILD patients compared to HS (p < 0.05 and p < 0.001, respectively).