Although the minimal evaluation of anemia must include the complete blood count, the determination of serum ferritin, sideremia, serum transferrin, and transferrin saturation index (TSAT—indicator of iron usable for erythropoiesis) necessary for the evaluation of iron deficiency, and the determination of C-reactive protein (CRP—indicator of inflammation, necessary for the evaluation of anemia from chronic diseases) [39], within the studied group no data on the transferrin saturation index were available. The gene discussed is CRP; the disease is Iron deficiency anemia.