Immunogen sequence: EGRTSFPEDT VITYKCEESF VKIPGEKDSV ICLKGSQWSD IEEFCNRSCE VPTRLNSASL KQPYITQNYF PVGTVVEYEC RPGYRREPSL SPKLTCLQNL K. CD55 (decay-accelerating factor, DAF) is a GPI-anchored membrane glycoprotein that protects autologous cells from classic