severity of adverse event AE severity G4 AE severity Grade 4 Web: http://ncicb.nci.nih.gov/xml/owl/EVS/ctcae.owl#Grade_4_Adverse_Event a severity of AE that has life-threatening consequences, for which urgent intervention is indicated, that puts the patient is at risk of death at the time of the event if immediate intervention is not undertaken, or that causes blindness or deafness (need to decide if unilateral or bilateral). Note the AE severity Grade 4 equals to CTCAE G4 AE severity. CTCAE4: E10008 (Grade 4 Adverse Event) YH, SS