For this review, we performed a literature search on the PubMed database (1988 - Present date) using combinations of multiple keywords and Medical Subject Heading (MeSH) terms - anemia, ESRD, erythropoietin, dialysis, chronic kidney disease, patient satisfaction, etc. The study types that were reviewed included review articles, meta-analyses, systematic reviews, multicenter studies, randomized clinical trials, excerpts from various journals and documents, and clinical trials. Here, EPO is linked to anemia (phenotype).