To explore the potential roles of FRMD3 in breast cancer, we ectopically overexpressed FRMD3 in T47D and MDA-MB-231 cell lines (with low FRMD3) by stable transfection of the FRMD3-expressing vector (pcflag-FRMD3) or knockdown FRMD3 in the MCF10A cell line (with high FRMD3) using lentivirus expressing shRNA and GFP. The gene discussed is FRMD3; the disease is breast carcinoma.