Clone 25.3F4 has been reported to be a mouse monoclonal antibody specific to the human gene, C4A, or Complement C4A (Rodgers blood group). Other suppliers describe clone 25.3F4 to be a mouse monoclonal antibody against human C4B, or complement C4B (Chido blood group). Indicated applications for antibody clone 25.3F4 include Western blot and ELISA.