In one embodiment, an isolated antibody or functional fragment thereof which binds an antigenic peptide sequence of human FOXC1 is provided herein. Such antibodies or functional fragments may be used to diagnose, prognose or treat basal-like breast cancer. The antibody or functional fragment may be a monoclonal antibody produced by a hybridoma cell line. Thus, a hybridoma cell line that produces a FOXC1 monoclonal antibody which binds an antigenic peptide sequence of human FOXC1 as described above is also provided.