PTH and renal cell carcinoma: The differential metabolites were associated with Pyrimidine metabolism, Nicotinate and nicotinamide metabolism, Nucleotide metabolism, Renal cell carcinoma, Arginine biosynthesis, Oxidative phosphorylation, Histidine metabolism, Sulfur metabolism, Citrate cycle (TCA cycle), Parathyroid hormone synthesis, secretion and action (Figure 5B).