PTEN and serous adenocarcinoma: Briefly, while examining the role of KRASG12D and PTEN signaling in granulosa cell development, they noted in triple transgenic mice (Ptenfl/fl;KrasG12D;Amhr2-Cre) that the loss of Pten and gain of KrasG12D in the OSE led to the development of low grade serous adenocarcinomas.