N K ▁path way ▁is ▁imp licated ▁in ▁a ▁number ▁of ▁phys i ological ▁processes ▁and ▁involves ▁J N K s ▁– ▁kin ases ▁responsible ▁for ▁the ▁ph osph ory lation ▁of ▁a ▁down stream ▁protein ▁called ▁c - J un . ▁This ▁further ▁leads ▁to ▁the ▁increase ▁in ▁expression ▁and ▁activity ▁of ▁specific ▁trans cription ▁factors ▁that ▁respond ▁to ▁a ▁variety ▁of ▁cell ular ▁stress ors , ▁growth ▁factors ▁and ▁cy tok ines . ▁The ▁activation ▁of ▁the ▁J N K ▁signal ▁trans du ction ▁path way ▁by ▁M AP 4 K 4 ▁has ▁been ▁imp licated ▁in ▁apo pt otic ▁reg ulation ▁of ▁many ▁different ▁cell ▁types , ▁tum or igen esis ▁and / or ▁infl amm ation . ▁ ▁p 5 3 ▁ ▁p 5 3 ▁is ▁a ▁tum our ▁suppress or ▁gene ▁and ▁is ▁involved ▁with ▁cell ular ▁response ▁to ▁stress . ▁When ▁expressed , ▁the ▁cell ▁cycle ▁is ▁halt ed ▁in ▁the ▁G 1 ▁phase ▁and ▁can ▁indu ce ▁sen esc ence ▁or ▁apo pt osis . ▁Mut ations ▁to ▁the ▁p 5 3 ▁gene ▁are ▁often ▁found ▁in ▁many ▁types ▁of ▁can cers . ▁ ▁The ▁M AP 4 K 4 ▁gene ▁contains ▁four ▁binding ▁sites ▁for ▁p 5 3 . ▁Upon ▁binding , ▁p 5 3 ▁up - reg ul ates ▁M AP 4 K 4 ▁expression ▁leading ▁to ▁the ▁activation ▁of ▁the ▁J N K ▁signal ing ▁path way . ▁si R NA ▁knock down ▁experiments ▁have ▁also ▁shown ▁a ▁reduction ▁of ▁p 5 3