▁thy roid , ▁bl ad der , ▁and ▁ad ren al ▁g lands . ▁It ▁is ▁also ▁found ▁in ▁the ▁end oth el ium ▁cells ▁of ▁the ▁blood - bra in ▁bar rier . ▁ ▁C lin ical ▁significance ▁ ▁Effect ▁of ▁polym orph isms ▁▁ ▁C ertain ▁polym orph isms ▁in ▁the ▁AB CC 1 ▁gene ▁have ▁been ▁shown ▁to ▁be ▁connected ▁with ▁an ▁increased ▁sus cept ibility ▁to ▁certain ▁types ▁of ▁cancer . ▁A ▁G 2 1 6 8 A ▁polym orphism ▁and ▁polym orph isms ▁found ▁in ▁the ▁ 3 '- UT R ▁region ▁of ▁the ▁gene ▁have ▁been ▁shown ▁to ▁have ▁a ▁connection ▁with ▁increased ▁sus cept ibility ▁to ▁lung ▁cancer , ▁especially ▁in ▁Chinese ▁populations . ▁Car riers ▁of ▁the ▁G 2 1 6 8 A ▁polym orphism ▁contract ▁lung ▁cancer ▁at ▁a ▁rate ▁nearly ▁four ▁times ▁higher ▁than ▁those ▁individuals ▁that ▁do ▁not ▁have ▁the ▁mut ation ▁in ▁the ▁gene . ▁Pol ym orph isms ▁within ▁the ▁AB CC 1 ▁gene ▁also ▁tend ▁to ▁have ▁a ▁substantial ▁effect ▁on ▁the ▁sever ity ▁of ▁a ▁disease . ▁Ex amples ▁of ▁these ▁dise ases ▁includes ▁c yst ic ▁fib ros is ▁( CF ) ▁and ▁chron ic ▁ob struct ive ▁pul mon ary ▁disease ▁( CO PD ). ▁In ▁reference ▁to ▁c yst ic ▁fib ros is , ▁individuals ▁with ▁a ▁G - 2 6 0 C ▁polym orphism ▁in ▁the ▁ 5 '- UT R ▁area ▁of ▁the ▁AB CC 1 ▁gene ▁t ended ▁to ▁have ▁a ▁much