FFAR3 and heavy chain disease: For example, HCD have been shown to promote G protein-coupled receptor 41 (GPR41) expression in the rumen, which acts as a receptor for SCFAs [27]; however, by knocking down GPR41 expression in bovine rumen epithelial cells, Meng et al. found that it decreased proliferation by mediating the PIK3-AKT-mTOR signaling pathway [28].