No significant association was found between the plasma PACAP-38 levels and MM-related renal disease either in the study of laboratory parameters (carbamide (n = 65, p = 0.4363, r = −0.09823, Spearman), creatinine (n = 65, p = 0.9126, r = 0.01388, Spearman), glomerular filtration rate (GFR) (n = 65, p = 0.9381, r = 0.009821, Spearman) indicative of end-organ damage, or when the patients were divided into groups with (n = 43) and without renal impairment (n = 22) (p = 0.6448) (Table 2). This evidence concerns the gene ADCYAP1 and kidney disorder.