FASTER, PLEASE! Heart Attack-Related Scarring Could Be Treated With New Protein Patch That Stimulates Tissue Regeneration. “The protein Follistatin-like 1 (FSTL1) was found to stimulate cultured heart cell muscles to divide. In animal models that had undergone an experimental form of myocardial infarction, a patch that applied these proteins proved to rebuild the damaged heart tissue and reduce scarring, two factors that current heart attack treatments fail to address.”