CAT and systemic sclerosis: MiR-29a, found decreased in SSc [58,59,71], and target SIRT1 (silent information regulator factor 2–related enzyme 1) histone deacetylase can deacetylate the FoxO factors and consequently regulate the expression of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and thioredoxin (TRX) [91].