MMP9 and Calcium nephrolithiasis: By querying the miRdSNP (57) and SNPinfo (58) databases, we found that the rs3737787 SNP is located in the binding site of miRNAs, including miR-148a-3p, miR-148b-3p, and miR-152-3p, in the 3′UTR of USF1. Bu et al. suggested that the rs1056628 SNP in the 3'UTR of the matrix metallopeptidase 9 (MMP9) gene alters the expression levels of the MMP9 mRNA and protein by mediating the binding of miR-491-5p to MMP9 and subsequently affecting the susceptibility of Chinese populations to idiopathic calcium kidney stones (59).