An HG–MNs patch composed of gelatin methacryloyl hydrogel microneedle for delivery of galunisertib, a TGF-b (fibroblast activator) inhibitor, was extremely efficient for inhibition of TGF-β/Smad2 signaling, contributing to reduced cardiac fibrosis, protecting from myocardial hypertrophy, and improving cardiac output with a sustained release of up to 15 days after a single application [7]. Here, TGFB1 is linked to cardiac hypertrophy.