SOX3 and secondary hyperparathyroidism: Histological analysis of parathyroid gland size from wild-type and mutant Sox3 mice revealed that parathyroid gland areas in Sox3+/Y and Sox3−/Y mice were significantly greater, in keeping with diet-induced secondary hyperparathyroidism, in mice on the low diet, when compared to the control diet (Sox3+/Y = 3885 ± 1012 μm2/g vs 1824 ± 656 μm2/g, P = 0.007; and Sox3−/Y = 4672 ± 1914 μm2/g vs 2539 ± 684 μm2/g, P = 0.040, n = 4); however, there was no difference between Sox3+/Y and Sox3−/Y mice on each diet (normal diet P = 0.091; low diet P = 0.247) (Fig. 3G and H).