Fig. 2

Immunohistochemical Findings in breast cancer with signet ring cell differentiation (magnification × 200). A ER is constantly expressed and more than 90% of cancer cells are strongly positive. B PR expression in case 1 reaches 90%. C PR expression of case 2 is negative. D GCDFP15 was expressed in case 5. E GATA3 was strongly positive in all cases. F CK7 was positive and was down-regulated in signet-ring-like cells compared to surrounding invasive ductal carcinoma cells. G Villin expression was positive in case 3. H WT-1 was positive in cases 4. I CgA were positive in case 4