VEGFA and systemic sclerosis: The subgroup analysis performed due to the obvious overall heterogeneity (I2 = 98.35%, P <0.0001) revealed significantly higher VEGF levels in serum (SMD 0.48, 95% CI 0.28–0.67, P <0.0001) and plasma (SMD 0.86, 95% CI 0.49–1.24, P <0.0001) samples of patients with SSc (Figure 4C-i).