Although Gordon et al. [17] confirmed that Pit1 recognizes the DNA sequences in the mouse TSHβ gene corresponding to those sites in the rat and human genomes using DNA foot printing, overexpression of Pit1 had a minimal effect on the activity of the TSHβ promoter in TtT97 TSHoma or thyrotroph-derived αTSH cells. This evidence concerns the gene TSHB and TSH-secreting pituitary adenoma.