The function of ERFE (erythroferrone, ENSG00000178752) is as follows. Iron-regulatory hormone that acts as an erythroid regulator after hemorrhage: produced by erythroblasts following blood loss and mediates suppression of hepcidin (HAMP) expression in the liver, thereby promoting increased iron absorption and mobilization from stores (PubMed:24880340, PubMed:30097509, PubMed:31800957). Promotes lipid uptake into adipocytes and hepatocytes via transcriptional up- regulation of genes involved in fatty acid uptake (By similarity). Inhibits apoptosis and inflammatory response in cardiomyocytes via promotion of sphingosine-1-phosphate (S1P) and cAMP-dependent activation of AKT signaling (By similarity). Inhibits autophagy induced by nutrient deficiency in hepatocytes via promoting the phosphorylation of IRS1, AKT, and MTOR, and thereby subsequent activation of the AKT- MTOR signaling pathway (By similarity). Negatively regulates the differentiation of osteoblasts, potentially via sequestering BMP2, and thereby inhibits the activation of SMAD signaling (By similarity). The reduction in BMP2 signaling in osteoblasts also results in an increase in expression of the osteoclastogenesis-promoting factors TNFSF11/RANKL and SOST, thereby indirectly promotes bone resorption (By similarity). {ECO:0000250|UniProtKB:Q6PGN1, ECO:0000269|PubMed:24880340, ECO:0000269|PubMed:30097509, ECO:0000269|PubMed:31800957}.