Hormone involved in the regulation of erythrocyte proliferation and differentiation and the maintenance of a physiological level of circulating erythrocyte mass. Binds to EPOR leading to EPOR dimerization and JAK2 activation thereby activating specific downstream effectors, including STAT1 and STAT3. {ECO:0000269|PubMed:28283061}.,Beta strand (4); Chain (1); Disulfide bond (2); Glycosylation (4); Helix (9); Mutagenesis (1); Natural variant (8); Sequence conflict (3); Signal peptide (1),Produced by kidney or liver of adult mammals and by liver of fetal or neonatal mammals.,Microvascular complications of diabetes 2 (MVCD2) [MIM:612623]: Pathological conditions that develop in numerous tissues and organs as a consequence of diabetes mellitus. They include diabetic retinopathy, diabetic nephropathy leading to end-stage renal disease, and diabetic neuropathy. Diabetic retinopathy remains the major cause of new-onset blindness among diabetic adults. It is characterized by vascular permeability and increased tissue ischemia and angiogenesis. Note=Disease susceptibility is associated with variations affecting the gene represented in this entry.; Erythrocytosis, familial, 5 (ECYT5) [MIM:617907]: An autosomal dominant disorder characterized by increased serum red blood cell mass, and elevated serum hemoglobin and hematocrit. Some patients have increased serum erythropoietin levels. {ECO:0000269|PubMed:27651169, ECO:0000269|PubMed:29514032}. Note=The disease is caused by mutations affecting the gene represented in this entry.; Diamond-Blackfan anemia-like (DBAL) [MIM:617911]: An autosomal recessive hematologic disease characterized by severe red cell hypoplastic anemia, selective absence of red cell precursors and progenitors seen on bone marrow biopsy, and increased serum erythropoietin. {ECO:0000269|PubMed:28283061}. Note=The disease is caused by mutations affecting the gene represented in this entry.