511THE ROLE OF TRANSFORMATION GROWTH FACTOR (TGF-Β1)PROTEIN IN IRAQI LUNG CANCER CELLS AND STROMALung cancer is the most common cancer world wide. The majority of the cases now occur in the developing countries in percentage 55%. TGF-β immunosuppressive cytokines inhibit anti-tumor immune cells such as CD8+ and Th1 cells in established cancer tissues, further facilitating cancer progression . TGFβ expression in tumors vary and include the cancer cells themselves as well as various cells of the tumor stroma, and extracellular matrix of tissue .TGF- β is secreted into the extracellular matrix of tumor cells as a latent protein complex. TGF-β plays an indispensible, yet complex, role in carcinogenesis and the progression of tumors. TGF-β1 protein expression in lung tumor cells and strom (fibroblast and matrix) were studied by using immuno-histochemical technique in 30 NSCLC tissue samples and 22 bengin tissue. TGF-β1 protein expression was positive expressed in malignant samples 25/30(83.3%)compared to bengin samples 16/30 (72.7%)with significant differences (p= 0.0401,chi-3.877).TGF-β1 expression in cancer cells samples and stromal cells samples not related with the age but it was high significant association with male ,Sqcc type and poorly differentiated with p≤0.001for each one. TGF-β1 expression (Moderate and high intensity) of matrix were showed high significant differences in malignant samples compared to benign samples(p≤0.00). Cancer cells ,stromal cells and Extracellular matrix highly TGF- β1 +expression ,suggesting the important role of the stroma surrounding tumor to enhance the carcinogenesis of lung cancersuhadhatim@yahoo.comResearch592014Lung Cancer,Stroma,TGF-β1Suhad Faisal Hatem Almugdadi,Amna Nsyif Jassim,Ban Abbas Abd-Almajeed,Wisam abdullatif,Maha Mahamommed Alsayyid Pharmacy College, Al-Mustansryia University, Baghdad, Iraq,Science College for women, Baghdad University, Baghdad, Iraq,Medicine College, Alnahrin University, Baghdad, Iraq,Specialized Surgery Hospital , Medical City, Baghdad, Iraq,Oncology Teaching Hospital, Baghdad, Iraq