B7H4, also known as B7-S1 or VTCN1, is a type I transmembrane protein. In normal healthy tissues, B7H4 is expressed at relatively low levels, while in many solid tumors such as breast cancer, ovarian cancer, and endometrial cancer, it is highly expressed, with its expression levels being inversely correlated with prognosis.
Because it belongs to the B7 family, experiments have shown that it can bind to T cells and inhibit their activity. Being overexpressed on the surface of tumor cells and showing a negative correlation with patient treatment benefits, as a T cell co-inhibitory checkpoint, B7H4 appears to be an ideal target for treating solid tumors.
