Genetic polymorphism G6721T (rs.7003908) in gene encoding DNA-dependent protein kinase (DNA-PKcs, encoded by the XRCC7 gene) has been defined. In order to get more insight into the genetic structure of Iranian population the present study was carried out on Iranian Persian population living in Shiraz (Fars province, southwest Iran). The total study subjects consisted of 935 (195 males, 740 fema...