In organs that do not express klotho, or in a state of klotho deficiency, FGF23 can activate FGFR4 and induce the phosphorylation of phospholipase γ (PLCγ), leading to hypertrophic growth in cardiac myocytes and the production of inflammatory cytokines in the liver (4, 5). This evidence concerns the gene KL and hyperinsulinemic hypoglycemia, familial, 4.