The research indicated that leptin levels are significantly lower in patients with the active phase of SSc than in inactive (1.92 ± 2.90 vs. 7.02 ± 7.65 ng/ml) and this fact harmonizes with the theory of Th2 lymphocytes domination in the early, active stage with enhanced fibrosis and Th1 in the latter inactive stage of SSc [15]. The gene discussed is LEP; the disease is systemic sclerosis.