HPGDS and nasopharyngeal carcinoma: A 5.71-fold risk of nasopharyngeal cancer has been reported in cases carrying glutathione-S-transferases (GSTs) such as GSTT1, GSTM1, and CYP1A1 MspI genotypes, suggesting that cross-linking between these genes may modulate nasopharyngeal cancer susceptibility, with similar results reported in HNCs17,46,62,71,75.