- Interleukin-1 beta enhances and interferon-gamma suppresses activin A actions by reciprocally regulating activin A and follistatin secretion from bone marrow stromal fibroblasts. Abe, M., Shintani, Y., Eto, Y., Harada, K., Fujinaka, Y., Kosaka, M., Matsumoto, T. Clin. Exp. Immunol. (2001)