PGR and breast neoplasm: Moreover, the breast tumors also presented solid nest formation and comedo necrosis with stromal invasion and the following findings: ER (−), PR (−), HER2 (−), CA125 (+), CK7 (+), CK20 (−), p53 (+), mammaglobin (−), and gross cystic disease fluid protein 15 (GCDFP15 (−)) (Fig. 3b).