FSCN1 and ductal breast carcinoma in situ: In the present report, we used immunohistochemical (IHC) analysis to detect FSCN1 expression in a series of paraffin-embedded breast lesion tissue, including that from usual ductal hyperplasia (UDH), ductal carcinoma in situ (DCIS), and invasive ductal carcinoma (IDC), and analyzed the relationship between FSCN1 and TNBC or epidermal growth factor receptor (EGFR).