TFRC and Schnyder corneal dystrophy: Also, sTfR concentrations show opposite trends in the two groups being negatively correlated with MCV and MCH in the control group (r2 = 0.0946, p = 0.0127 and r2 = 0.0915, p = 0.0143, respectively) and positively correlated with MCV and MCH in the SCD group (r2 = 0.1593, p = 0.0005 and r2 = 0.0283, p = 0.1548, respectively) (Figures 2 and 3).