Immunogen sequence: KNGSWLYAMC RGIEHDPVKP RQLPKTIGCS KNFPGKTALA TREQVQWWLL QLAQELEERL TKDRNDNDRV ATQLVVSIRV QGDKRLSSLR RCCALTRYDA HKMSHDAFTV IKNCNTSGIQ TEWSPPLTML FLCATKFSAS APSSSTDITS FLS. The XPA gene encodes a zinc metalloprotein that preferentially b