GSTM1 and Familial prostate cancer: A recent multi-institutional case-control study including 10 studies (1715 cases and 2363 controls) among subjects of African descent (African-American, African-Caribbean and African) has provided new data for this ethnic group [14]: homozygous deletion of GSTM1 or of GSTT1 was found to be inversely associated with the risk of prostate cancer.