Anemia is a common complication in patients with solid tumors, and the etiology of cancer-related anemia is multifactorial, ranging from direct effects of cancer such as tumor hemorrhage and direct effects of bone marrow invasion, results of cancer treatment itself such as chemotherapy, radiotherapy, tyrosine kinase inhibitors (TKIs), and monoclonal antibodies-induced cell death, or chemical factors produced by cancer such as autoantibodies, inflammatory cytokines that affect erythropoietin production and block iron metabolism [20, 21]. Here, EPO is linked to cancer.