Hypoxia is a characteristic of most tumor and neurodegenerative diseases with low oxygen condition caused by numerous environmental and genetic aberrations.Study of Hypoxia in neurodegenerative diseases is very important due to its close relation with cellular proliferation,differentiation,necrotic and apoptotic cell death.Low oxygen condition generates stress in the cells and this stress inhibits cellular pathways.The main victim of stress condition is mitochondria,dysfunction of mitochondria leads to apoptotic cell death.The cellular self defence mechanism reduces the stress by induction of different pathways; different cells have different strategy to cope the stress conditions.Several proteins are expressed under the hypoxic conditions among them one is BNIP3,it is Bcl-2 19 kDa interacting protein 3 belongs to pro-cell death protein family member Bcl-2,and is allied with the pathogenesis of various diseases.The role of Bnip3 is controversial due to its different localization on cellular components.Bnip3 is highly expressed under stress conditions.The different cell lines have different expression levels.