TGF beta(transforming growth factor beta), with 390-amino acid protein (about 43 kDa), is a multifunctional peptide that controls proliferation, differentiation, and other functions in many cell types. In mammals, three isoforms of TGFbeta, that is, beta1, beta2,and beta3,are known. TGF beta is one of numerous inhibitory factors produced by cancer cells that regulate antitumor immunity. TGF beta1 takes part in the local response in the course of primary lung cancer and TGFbeta1 is thought to be implicated in breast cancer progression.TGFbeta1 also plays a critical role in the downregulation of microglial responses minimizing brain inflammation and thus avoiding exacerbation of brain damage.