Immunogen sequence: VHARYACDDM EGQLVSIHSP EEQDFLTKHA SHTGSWIGLR NLDLKGEFIW VDGSHVDYSN WAPGEPTSRS QGEDCVMMRG SGRWNDAFCD RKLGAWVCDR LATCTPPASE GSAESMGPDS RPDP. CD23 is a 45 kDa glycoprotein that serves as a low-affinity receptor for IgE, playing a crucial