Infusion reactions, hypersensitivity reactions, anaphylaxis, and tumor lysis syndrome are oncologic emergencies that are seen in both inpatient and ambulatory settings. Advanced practice RNs (APRNs) are often the first providers to respond to those emergencies. During a session on Friday, April 12, 2019, at the ONS 44th Annual Congress in Anaheim, CA, Patricia Jakel, RN, MN, AOCN®, of the University of California, Los Angeles, Health System in Santa Monica, discussed oncologic emergencies and the APRN’s role in rapid identification of a diagnosis.