α-Mangostin has a wide range of biological actions, including, but not limited to, increasing the activity of caspase-3, caspase-8, and caspase-9, modulating cell cycle regulators, increasing the B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (Bax/Bcl-2) ratio, increasing reactive oxygen species (ROS) levels, inhibiting the phosphoinositide 3-kinase (PI3K) / protein kinase B (Akt) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathways, and reducing tumor volume in animal models [8,11,12,13,14]. The gene discussed is CASP8; the disease is neoplasm.