Park IK, Shultz LD, Letterio JJ, Gorham JD. TGF-beta1 inhibits T-bet induction by IFN-gamma in murine CD4+ T cells through the protein tyrosine phosphatase Src homology region 2 domain-containing phosphatase-1. J Immunol. 2005 Nov 01; 175(9):5666-74.