NAT1 and NAT2. Other cancer-related polymorphisms affect enzymes involved in the biotransformation of tumorigenic components of tobacco, such as N-Acetyltransferase 1 (NAT1) and 2 (NAT2), which actively participate in the metabolic activation of aromatic and heterocyclic amines to electrophilic intermediates. This evidence concerns the gene NAT1 and cancer.