In SCD patients who are not on hydroxyurea, transferrin saturation is not associated with hemoglobin concentration (Figure 1(a): see nonsignificant slope estimate for SCD group; Table 1: see statistically significant interaction effect for the SCD group; Table 2: see slope estimate for the SCD group) and has an inverse relationship with RBC counts (Figure 1(b): see statistically significant negative slope for the SCD group), as indicated by the significant interaction shown in Table 1 and the negative slope estimate (Table 2). This evidence concerns the gene TF and Schnyder corneal dystrophy.