Immunogen sequence: DDINIKQVLL NMRKYRMGLI QTPDQLRFSY MAIIEGAKCI KGDSSIQKRW KELSKEDLSP AFDHSPNKIM TEKYNGNRIG LEEEKLTGDR CTGLSSKMQD TMEENSESAL RKRIREDRKA TTAQKVQQMK QRLNENERK. T-cell protein tyrosine phosphatase (TC-PTP), also known as PTPT and PTPN2, is a