ASS1 and cancer: In conclusion, the dysregulation of the urea cycle in cancer is accompanied by the inactivation of ASS1, activation of CAD (carbamoyl-phosphate synthetase 2, aspartate transcarbamylase, and dihydroorotase), overexpression of NO, enhanced pyrimidine synthesis at the expense of purine, mutagenesis, increased cell proliferation, invasiveness, and survival, poor prognosis, and increased immunotherapy efficacy [1,10,76,78].