Source:http://linkedlifedata.com/resource/umls/id/C0764347
NCI: Glutathione S-transferases (GSTs) are a family of phase II enzymes which comprise at least four classes, a, m, p and q. The GSTM1 gene is one of the m-class forms and is classified into three genotypes, GSTM1A, GSTM1B, and GSTM1 (0/0). The GSTM1 (0/0) genotype due to inherited homozygous deletion of both alleles has no enzymatic activity. The GSTM1 (0/0) genotype has been possibly implicated in elevated risks of lung and urothelial cancer. (Japanese Journal of Clinical Oncology,Pages 657-660).