The research status of a new member of B7 family HHLA2 in human malignant tumors

HHLA2, which is a new member of B7 family of the second signal molecules, provides coinhibitory or costimulatory signals of the activation of T cell while binding to different receptors.Studies have shown that HHLA2 was rarely expressed in normal human tissues, but it was highly expressed in a variety of malignant tumors, suggesting that HHLA2 may be involved in the immune escape and the development of malignant tumors.Thus, HHLA2 might be a potential target for tumors immunotherapy.Further research on the expression of HHLA2 in malignant tumors is of great significance. Key words: HHLA2; B7 family; TMIGD2; Malignant tumor; Immunotherapy