Bladder cancer arises from the epithelial lining of the urinary bladder, and it 
is known as transitional cell carcinoma (TCC). Tobacco smoking is the main known 
contributor to urinary bladder cancer. However thirty percent of bladder tumors 
probably result from occupational exposure in the workplace to carcinogens. 
Immunotherapy by intravesicular delivery of Bacillus Calmette–Guérin (BCG) is 
used to treat and prevent the recurrence of superficial bladder cancer. 
Successful BCG immunotherapy for bladder cancer is associated with proper 
induction of T helper (Th)1 immunity. In bladder cancer patients after 
intravesicular BCG, urine was found to contain high levels of IP-10, and 
Interferon (IFN)-γ. TCC and endothelial cell lines were able to secrete IP-10 in 
response to BCG or IFN stimulation in vitro. Furthermore intravesicular BCG 
induces a cytokine-rich urinary microenvironment that is inhibitory to human 
endothelial cells and it is anti-angiogenetic by the induction of Th1 
chemokines. Other studies suggest that therapeutic strategies involving Th1 
induction and Th2 dampening may improve responses to immunotherapy. Further 
studies are needed to evaluate the IP-10 in circulation, and urine, as 
prognostic marker of bladder cancer patients, also in relation to BCG 
immunotherapy