One pilot study randomized 84 patients with hip fracture to receive transfusion if Hb levels dropped below the predefined threshold of 100 g/L, or to receive transfusion only for symptoms of anemia or a Hb of less than 80 g/L, but no firm conclusions could be drawn from that study (Carson et al. 1998b). The gene discussed is GSTM1; the disease is anemia.