definiens: means any molecule ( including Antibodies, peptides andchemical compounds ) that ( a ) has been raised, engineered or otherwise optimized to bind specifically anddirectly to CSF1R and ( b ) ( i ) competes for binding to CSF1R with colony stimulating factor 1 and/or interleukin-34, or ( ii ) once bound to CSF1R, ( A ) exhibits antagonistic activity against CSF1R with, in the case of a chemicalcompound, a half maximal inhibitory concentration ( IC50 ) of * * * or less in a kinase activity assay for CSF1Ractivity or ( B ) depletes cells expressing CSF1R, including by blocking dimerization of CSF1R or throughAntibody - dependent cell - mediated cytotoxicity, Antibody - mediated cytotoxic - induced apoptosis, redirected Tcells or immune effector cells to which such Antibody is grafted