ARTN and anemia: Further, EPO administration for patients with cancer significantly improves hematological responses and decreases the need for RBC transfusion (237); however, caution is required in patients with cancer and anemia as, while EPO may influence the curative effect of ICI therapy by restoring Ter-cell numbers and serum artemin concentration (166), EPOR are present on various types of tumor cell and tumor cell lines, and EPO/EPOR may contribute to tumor progression and metastatic progression (238).