Apoptosis may be initiated by various types of cell pressure such as heat shock and ultra-violet irradiation. The Bcl 2 members of the family play a vital role in regulating apoptosis. Bcl 2 family comprises three PF 573228 subfamilies: antiapoptotic members, such as Bcl 2/Bcl XL, proapoptotic members, such as Bax, Bak, and Bok, and BH3 only proteins, such as Bid, Bim, Puma, and Bmf. The proapoptotic protein Bax plays a crucial role in apoptosis. In addition, the c Jun N final kinase signaling pathway promotes Bax service by phosphorylating Bim, suggesting that Bim offers a molecular link between the Bax dependent mitochondrial apoptotic machinery and the JNK signaling pathway. Subsequent exposure to an stimulus, Bax undergoes a conformational change, leading to exposure of its C termini and N and to its mitochondrial targeting. Inside the mitochondrial membrane, oligomerized Bax helps mitochondrial membrane permeabilization, resulting in cytochrome c release from mitochondria. However, cells have self fixing system to suppress apoptosis under dangerous conditions, which is often achieved by members of the Retroperitoneal lymph node dissection heat shock protein family. Heat shock proteins are a couple of highly conserved proteins and they function as molecular chaperones. A well known subgroup of Hsps will be the heat shock protein 70 family. There are numerous Hsp70 members of the family, including pressure inducible Hsp70, constitutively indicated Hsp70, mitochondrial Hsp75, and GRP78. The expression of Hsp70 can be induced by a number of stresses, including UV irradiation, warmth shock and oxidative stress. Hsp70 is claimed to protect cells from apoptosis induced by various stresses and providers. It might block the apoptotic process at different levels. Most importantly, recent studies have suggested that Imatinib Glivec Hsp70 prevents Bax translocation to mitochondria and blocksmitochondrial membrane permeabilization, although its molecularmechanisms aren’t clear currently. The purpose of this study is to investigate how Hsp70 inhibits Bax activation in UV induced apoptosis. To ascertain the molecular mechanisms associated with this approach, this study focuses on: the service of the JNK/Bim/Bax signaling pathway after UV irradiation, inhibitory effects of Hsp70 on the JNK/Bim/Bax pathway in UV activated apoptosis, the relationship between Hsp70 and Bax. We used antibodies against Hsp70, JNK and Bax and r JNK. CFP Bax was supplied by Drs. Gilmore and Streuli, YFP Hsp70 was something special from Dr. Morimoto of Northwestern University, and pDsRedMit was supplied by Dr. Gotoh. Hsp70 small hairpin RNA and Scr were supplied by Dr. Tolkovsky.