Notably, fibroblast growth factor 21 (Fgf21), another ATF4-inducible gene70, was markedly upregulated in the liver of SPF, but not GF, mice as early as one week post-LPD initiation (Fig. 2g, Extended Data Fig. 10). The gene discussed is FGF21; the disease is disseminated peritoneal leiomyomatosis.