- Stat5a inhibits IL-12-induced Th1 cell differentiation through the induction of suppressor of cytokine signaling 3 expression. Takatori, H., Nakajima, H., Kagami, S., Hirose, K., Suto, A., Suzuki, K., Kubo, M., Yoshimura, A., Saito, Y., Iwamoto, I. J. Immunol. (2005)