IL1A and systemic sclerosis: In contrast, the levels of IL-6 (53.6±9.7 vs. 5.4±3.4, P<0.0001), IL-1α (83.2±11.2 vs. 1.2±1.1, P<0.002) and IL-23 (49.1±7.3 vs. 5.3±0.6, P = 0.003) were significantly higher in SSc as a whole compared with controls (Figure 3b–d).