Consonant with this, kidney stone formers were recently shown to exhibit higher CYP24A1 expression in circulating monocytes compared to nonstone formers when individual 1,25(OH)2 vitamin D3 concentrations were taken into account (i.e., higher circulating 1,25 (OH)2 vitamin D3 /monocyte CYP24A1 expression ratios).40 Here, CYP24A1 is linked to nephrolithiasis.