Monoclonal Antibody 1F5

**Semantic type:** Amino Acid, Peptide, or Protein|Immunologic Factor|Pharmacologic Substance

**Definition:** A murine monoclonal antibody directed against CD20, a cross-membrane ion channel phosphoprotein expressed by B cells, with potential antineoplastic activity. MOAB 1F5 binds to CD20, thereby directly inhibiting B-cell proliferation and differentiation. When cross-linked by secondary anti-mouse antibodies or Fc receptor-bearing cells, MOAB 1F5 may induce activation of B-cell protein tyrosine kinases, increases in B-cell intracellular calcium ion concentrations, and B-cell caspase activation, resulting in apoptosis of B cells expressing CD20. (NCI04)

**Synonyms:** - Anti-CD20 Monoclonal Antibody 1F5 - MOAB 1F5