In an experimental study in rats with AF (Yao et al., 2020), suppression of MIAT, an inhibitor of miR133a-3p expression, reduced atrial fibrosis, inhibited the expression of genes that promote collagen deposition, and led to a decrease in CTGF and TGF-β1 levels. The gene discussed is TGFB1; the disease is atrial fibrillation.