Activin induces x-zone apoptosis that inhibits luteinizing hormone-dependent adrenocortical tumor formation in inhibin-deficient mice. - Beuschlein,F.; Looyenga,B.D.; Bleasdale,S.E.; Mutch,C.; Bavers,D.L.; Parlow,A.F.; Nilson,J.H.; Hammer,G.D. (Mol Cell Biol, 2003)