PIK3CA and endometrial cancer: Taken together, these preclinical data suggested that in endometrial cancer patients PI3KCA mutations located outside exons 9 and 20 may also represent potential targets for selective pan-Class I PI3K inhibitors such as copanlisib (BAY 80-6946) and accordingly, patients harboring PIK3CA mutation in exons different from 9 and 20 were also eligible for enrollment in the GY008 trial.