The present invention relates to antibodies (including anti-B7-H4 antibodies) and their antigen-binding fragments and to other molecules (including fusion proteins that bind to the cognate antigen/receptor, etc.) that are capable of immunospecifically binding to B7-H4 and the uses of such molecules in the diagnosis and the treatment of cancer and other diseases. The invention particularly concerns the use of such molecules to retard or prevent tumor growth, inhibit tumor-mediated suppression, eliminate tumors and/or deplete or block the activity of tumor associated macrophages (“TAMs”) so as to alter their activity and/or decrease TAM—mediated immune suppression.
