Interestingly, we observed an increased expression of the CAMP gene after exposure to uremic serum in vitro, and this was partially diminished by vitamin D. Grabulosa et al. demonstrated that the serum level of CAMP was higher in hemodialysis patients than that in pre-dialysis CKD patients (47), while other studies have shown that uremia may lower the serum levels of CAMP (20). Here, CAMP is linked to uremia.