In our PPI analysis (Supplementary Figure 18), strong interactions are found among pleiotropic genes, such as NDST2, CAMK2G, RASGRF1, IGF2R, SORT1, and TRIB1. These genes were reported to be associated with organic cation transmembrane transporter, such as organic anion transporters oat1 and oat3, and organic cation transporters oct1 and oct2, which was also altered with chronic kidney failure in rats (Komazawa et al., 2013). Here, SLC22A2 is linked to chronic renal failure syndrome.