Breast lobules and UDH (Fig. 4a, b) only expressed EZH2 in a low level (Fig. 4d, e), whereas EZH2 was strongly overexpressed in high-grade DCIS (Fig. 4c, f), associated with invasive triple-negative breast carcinoma, and homogeneously strong positivity in 90 ~ 100 % cells was observed; however, expression of EZH2 in low-grade DCIS was variable, with 55 % cases showing overexpression. Here, EZH2 is linked to ductal breast carcinoma in situ.