The abundances of NAGS, CPS1, and citrin mRNA and proteins in the lung, brain, esophagus, and stomach tissues are 10–1000 times lower than in the liver, and the expression of the three genes is two- to four-fold higher in glioblastoma, glioblastoma multiforme, lung adenocarcinoma, stomach adenocarcinoma, and stomach and esophagus carcinoma samples. Here, NAGS is linked to gastric adenocarcinoma.