Peptide sequence: RTHAIKFVEG LIVTLSPRMA DSEIPRRQEH DISLDRIPRD HPYIQYNVLW Sequence homology: Cow: 93%; Dog: 93%; Guinea Pig: 93%; Horse: 93%; Human: 100%; Mouse: 93%; Rabbit: 100%; Rat: 93%. The CD4 antigen is involved in the recognition of MHC class II m