AGR2 and breast cancer: AGR2 expression was most frequently seen in tumors of the female genital tract, particularly adenocarcinomas (up to 100%), various breast cancer subtypes (57.1%–100%), urothelial carcinoma (74.6%–100%), adenocarcinomas of the upper and lower gastrointestinal tract (93.6%–99.6%), and pancreaticobiliary cancers (65.2%–98.2%).