IL18 and systemic sclerosis: One previous study has looked at IL‐1α, IL‐1β and IL‐18 (as well as the IL‐1 family cytokine IL‐33) in a relatively modest‐sized Chinese cohort (56 patients and 56 HC) and found that only serum IL‐1β and IL‐33 were higher in SSc in multivariable analysis.