Destruxin B, isolated from entomopathogenic fungus Metarhizium anisopliae, is one of the cyclodepsipeptides with insecticidal and anticancer activities. Destruxin B induces apoptosis via a Bcl-2 Family-dependent mitochondrial pathway in human nonsmall cell lung cancer cells. Destruxin B significantly activates caspase-3 and reduces tumor cell proliferation through caspase-mediated apoptosis, not only in vitro but also in vivo.