▁also ▁known ▁as ▁GR X 2 , ▁is ▁a ▁gl ut are do x in ▁family ▁protein ▁and ▁a ▁th i ol - dis ulf ide ▁ox id ored uct ase ▁that ▁maintain s ▁cell ular ▁th i ol ▁home ost asis . ▁This ▁gene ▁consists ▁of ▁four ▁ex ons ▁and ▁three ▁intr ons , ▁sp anned ▁ 1 0 ▁kil ob ase ▁pairs , ▁and ▁local ized ▁to ▁chrom os ome ▁ 1 q 3 1 . 2 – 3 1 . 3 . ▁ ▁Altern ative ▁sp lic ing ▁of ▁GL R X 2 ▁leads ▁to ▁three ▁is o forms ▁of ▁Gr x 2 . ▁One ▁is o form , ▁Gr x 2 a , ▁local izes ▁to ▁the ▁mit och ond ria , ▁is ▁u bi quit ously ▁expressed ▁in ▁t issues ▁( e . g . ▁heart , ▁ske let al ▁mus cle , ▁kid ney , ▁and ▁li ver ), ▁regul ates ▁mit och ond rial ▁re do x ▁home ost asis , ▁and ▁protect s ▁cells ▁against ▁ox id ative ▁stress . ▁I so forms ▁Gr x 2 b ▁and ▁Gr x 2 c , ▁both ▁local ized ▁to ▁the ▁nucle us ▁and ▁c yt os ol , ▁are ▁expressed ▁only ▁in ▁test es ▁and ▁cancer ▁cell ▁lines ▁and ▁facil itate ▁cell ular ▁different iation ▁and ▁transformation , ▁potentially ▁indu cing ▁tum or ▁pro gression . ▁ ▁Str ucture ▁ ▁Gene ▁▁ ▁The ▁trans cript s ▁of ▁mit och ond rial ▁and ▁nuclear ▁Gr x 2 ▁is