Liver fibrosis in the course of metabolic dysfunction-associated steatohepatitis (MASH) could be significantly reduced using CAR T-cells generated in vivo. Scientists at the Icahn School of Medicine at Mount Sinai have developed an experimental cell therapy that eliminates only one type of liver cell, the stellate cells that express fibroblast activation protein alpha (FAP). This strategy not only reduced fibrosis but also reversed liver damage.