FOLR1 and ovarian cancer: The MOv18 IgE trial has hailed the first-in-class IgE antibody, which is tested in a first-in-human phase I clinical trial at Guy’s Hospital, London, and three other trial centers in the U.K. This first-in-class IgE class antibody recognizes folate receptor alpha (FRα), a tumor-associated antigen expressed on a range of cancer types, including ovarian cancer [114].