Nitrosation of piperazine in the stomach.
D005753:Gastric Mucosa / Q000378:metabolism*; D006801:Humans; D008297:Male; D009602:Nitrosamines / Q000378:metabolism*; D010879:Piperazines / Q000378:metabolism*; D012306:Risk
D009602:Nitrosamines; D010879:Piperazines; C026156:N,N'-dinitrosopiperazine; C014711:1-nitrosopiperazine