Immunotherapy has evolved into the “fourth pillar” of cancer care, along with surgery, chemotherapy and radiation therapy, according to Laura S. Wood RN, MSN, OCN®, of the Cleveland Clinic Taussig Cancer Center in Ohio and Krista M. Rubin, MS, RN, FNP-BC, of Massachusetts General Hospital in Boston, who spoke during a session on Wednesday, April 10, 2019, at the ONS 44th Annual Congress in Anaheim, CA. Immunotherapeutic agents, however, are vastly different from chemotherapies and have a distinct toxicity profile that advanced practice nurses must be familiar with.