Researchers at Princeton University and Rutgers Cancer Institute elucidated that anemia in patients with bone metastases stems from tumor cells hijacking specialized iron-transporting erythroblast island macrophages in the bone marrow. This cellular commandeering deprives red blood cells of iron essential for their production and simultaneously supports the growth of metastatic tumors in bone, revealing a novel metabolic crosstalk with implications for therapeutic interventions targeting both anemia and metastasis.