Effects of the Janus Kinase Inhibitor, Tofacitinib, on Testicular Leydig Cell Hyperplasia and Adenoma in Rats, and on Prolactin Signaling in Cultured Primary Rat Leydig Cells. - Chapin RE; Ball DJ; Radi ZA; Kumpf SW; Koza-Taylor PH; Potter DM; Mark Vogel W (Toxicological sciences : an official journal of the Society of Toxicology, 2017)