SLC40A1 and type 2 diabetes mellitus: As shown in Table 2, FPN expression in the duodenum was increased significantly in patients with T2DM with anemia compared to patients without IDA and controls; 1.17 (0.89–1.46), 0.76 (0.53–1.04), and 0.71 (0.64–0.86), respectively (p = 0.011).