Further study shows that ISO treatment in gastric cancer cells initiated the activation of the Caspase-3 cascade, including the upregulation of cytochrome C, Bax/Bcl-2, and the cleavage of Caspase-3 as well as PARP, and finally resulted in mitochondrial homeostasis imbalance and apoptosis. The gene discussed is CASP3; the disease is gastric cancer.