Anisomycin is an antibiotic initially produced by Streptomyces that retains no antibacterial activity. Anisomycin exhibits neuromodulatory and anticancer chemotherapeutic activities. Anisomycin inhibits peptidyl transferase in the 80S ribosome, suppressing protein synthesis. In animal models, anisomycin decreases facilitation of fear conditioning pre-shock; it also inhibits consolidation and reconsolidation in incentive learning models. Anisomycin induces apoptosis and inhibits cell proliferation in breast cancer cells. Anisomycin also inhibits growth of Ehrlich ascites carcinoma cells in vitro and in vivo, inducing caspase-dependent apoptosis and DNA strand breakage. Additionally, this compound inhibits expression of CDK2 and activates p53, p21, and p27, inducing cell cycle arrest and inhibiting cell proliferation in Jurkat T cells.