IGHG3 and systemic sclerosis: The median serum levels of total IgG [10.04 g/l (IQR 8.8–11.42 g/l) vs. 9.21 g/l (IQR 6.6–9.94 g/l), p > 0.05], IgG1 [5.09 g/l (IQR 4.29–6.38 g/l) vs. 5.04 g/l (IQR 3.79–5.57 g/l), p > 0.05], IgG2 [3.66 g/l (IQR 3.05–4.64 g/l) vs. 2.57 g/l (IQR 1.98–3.77 g/l), p > 0.05], IgG3 [0.58 g/l (IQR 0.41–0.67 g/l) vs. 0.77 g/l (IQR 0.28–1.19 g/l), p > 0.05], and IgG4 [0.23 g/l (IQR 0.15–0.44 g/l) vs. 0.43 g/l (IQR 0.07–0.65 g/l), p > 0.05] were similar between female and male SSc patients (Table 3).