NCIt definition : A semisynthetic formulation of the cytotoxic plant alkaloid homoharringtonine isolated
from the evergreen tree Cephalotaxus with potential antineoplastic activity. Omacetaxine
binds to the 80S ribosome in eukaryotic cells and inhibits protein synthesis by interfering
with chain elongation. This agent also induces differentiation and apoptosis in some
cancer cell types.;
Alternative definition : NCI-GLOSS: An anticancer drug that belongs to the plant alkaloid family of drugs.;