PBX1 and cystinuria: Although PBX1 was overexpressed by 3.3‐fold in patients with cystinuria compared to the control group, when we compared the gene expression findings with the genotyping, patients with the polymorphic homozygote genotype had underexpression of PBX1, while patients with heterozygote or wild‐type homozygote genotypes showed overexpression of PBX1.