Immunogen sequence: MARALCPLQA LWLLEWVLLL LGPCAAPPAW ALNLDPVQLT FYAGPNGSQF GFSLDFHKDS HGRVAIVVGA PRTLGPSQEE TGGVFLCPWR AEGGQCPSLL. CD41, also known as platelet glycoprotein IIb or ITGA2B, is a protein composed of two subunits: a 120 kDa alpha subunit and