In the study conducted by Khatami et al. VDR methylation analysis was performed in 30 consecutive recurrent kidney stone formers and 30 age and gender-matched CTRs, revealing a hypermethylation pattern of two VDR promoter regions, including 5 and 11 CpG sites, in cases related to CTRs [43] (Figure 2). This evidence concerns the gene VDR and nephrolithiasis.