We therefore incubated human primary monocytes in the media supplemented with 20% serum of each individual CKD patient and measured the mRNA levels of GPR68. Induction of mRNA expression of GPR68, TNFα, and IL-6 in human primary monocytes was detected when cells were incubated in 20% serum media (Fig. 8g). Here, GPR68 is linked to chronic kidney disease.