Ans: (b) PTENRef: WHO, FGT, Page 29-34Going with PTEN because it's the most common one mutated (Ref: WHO - >50%). P53 mutation is seen only in type 2 carcinomas, incidence of which is less. PTEN is seen in both type 1 and type 2 carcinomas.FeaturesType 1Type 2Prototypic formEndometrioid carcinomaUterine (papillary) serous carcinomaTypical patientPerimenopausal or early postmenopausal womenElderly women Background of endometrial hyperplasiaBackground of atrophic endometrium Low-gradeHigh-grade Estrogen-dependentNot estrogen-dependentEstrogen receptorUsually positive; high grade cases may be negativeNegativeMIB1 proliferation index (ki-67)LowHighp53Negative; high grade cases may be positiveDiffuse positivity