Expression of miR-638 in breast cancer tissue samples and cell lines. (A) Representative images before microdissection. Breast cancer tissue sections were double immunostained for smooth muscle actin (red) to elucidate the epithelial capsule (arrows). Different components, such as normal (N), ADH, DCIS and IDC are as indicated. (B) Expression of miR-638 in TNBC and non-TNBC cases. Expression of miR-638 was significantly downregulated in 3 of 10 TNBCs and 15 of 20 non-TNBCs when compared to normal. (C) Expression of miR-638 in breast cancer cell lines was downregulated compared to the immortalized MCF-10A cells. Results are displayed as mean data ± SE. (*P <0.05 and **P <0.01). ADH, atypical ductal hyperplasia; DCIS, ductal carcinoma in situ; IDC, invasive ductal carcinoma; TNBC, triple-negative breast cancer.