ANXA5 and neoplasm: Annexin V staining, that can distinguish cells beginning to undergo apoptosis (early apoptosis; low Annexin V/ propidium iodide [PI]-positive), or that are undergoing apoptosis (late apoptosis; high Annexin V/ high PI) or necrosis (high Annexin V/ low PI), was performed on live single-cell suspensions of ERMS tumor cells extracted post euthanasia.