CPS1 and neoplasm: Since the aberrant expression of two or more urea cycle genes is needed for the metabolic reprogramming of tumor cells [9], we used data mining approaches to identify tumor types with aberrant expression of NAGS, CPS1, and citrin genes that can increase the cytoplasmic concentration of CP and aspartate leading to higher CAD activity, biosynthesis of pyrimidine nucleotides, and dysregulation of the cellular pyrimidine–purine balance.