▁sp lic ed ▁trans cript ▁variants ▁encoding ▁distinct ▁is o forms ▁have ▁been ▁found ▁for ▁this ▁gene . ▁ ▁Gl ut ath ione ▁per ox id ase ▁ 1 ▁is ▁character ized ▁in ▁a ▁pol yal an ine ▁sequence ▁polym orphism ▁in ▁the ▁N - term inal ▁region , ▁which ▁includes ▁three ▁alle les ▁with ▁five , ▁six ▁or ▁seven ▁al an ine ▁( A la ) ▁repe ats ▁in ▁this ▁sequence . ▁The ▁alle le ▁with ▁five ▁A la ▁repe ats ▁is ▁significantly ▁associated ▁with ▁breast ▁cancer ▁risk . ▁ ▁Function ▁▁ ▁GP X 1 ▁is ▁u bi quit ously ▁expressed ▁in ▁many ▁t issues , ▁where ▁it ▁protect s ▁cells ▁from ▁ox id ative ▁stress . ▁Within ▁cells , ▁it ▁local izes ▁to ▁the ▁cy top las m ▁and ▁mit och ond ria . ▁As ▁a ▁gl ut ath ione ▁per ox id ase , ▁GP x 1 ▁functions ▁in ▁the ▁det ox ification ▁of ▁hydro gen ▁per ox ide , ▁specifically ▁by ▁catal yz ing ▁the ▁reduction ▁of ▁hydro gen ▁per ox ide ▁to ▁water . ▁The ▁gl ut ath ione ▁per ox id ase ▁also ▁catal y zes ▁the ▁reduction ▁of ▁other ▁organ ic ▁hydro per ox ides , ▁such ▁as ▁li pid ▁per ox ides , ▁to ▁the ▁corresponding ▁alco h ols . ▁GP x 1 ▁typically ▁uses ▁gl ut ath ione ▁( G SH ) ▁as ▁the ▁re duct ant , ▁but ▁when ▁gl ut ath ione ▁synth et ase ▁( G SS ) ▁is , ▁as