SH3BP2 (SH3 domain-binding protein 2) is a protein that comes from a gene located on Chromosome 4. It is widely expressed in hematopoietic cells, including: Macrophages, B and T lymphocytes, and osteoclast precursors. SH3BP2 has an N-terminal pleckstrin homology domain to bind differentially to the SH3 domains of certain proteins of signal transduction pathways, as well as a proline-rich domain and a C-terminal Src homology domain. It functions as an adaptor protein involved in signaling pathways, in concert with SRC kinases, SYK, and PLCγ, affecting immune cell activation, inflammatory signaling, and bone metabolism-- it is also associated with cherubism. It binds to phosphatidylinositol, linking the hemopoietic tyrosine kinase fes to the cytoplasmic membrane in a phosphorylation-dependent mechanism.