B7-H4 (B7S1 or B7X) is a member of B7 family and inhibits the T cell mediated response by inhibiting T cell proliferation, activation, and cytokine production. B7-H4 also inhibits the innate immune response by suppressing the growth of immunocyte, thereby allowing cancers to avoid immunologic surveillance. B7-H4 was overexpressed in many cancers, including non–small cell lung cancer, melanoma, breast cancer, ovary cancer, prostate cancer, esophagus cancer, stomach cancer, pancreas cancer, and kidney cancer, but not in normal tissues. B7-H4 may be associated with cancer progression and can be a prognostic marker in some cancers.
Qian Y, Sang Y, Wang F X C, et al. Prognostic significance of B7-H4 expression in matched primary pancreatic cancer and liver metastases[J]. Oncotarget, 2016, 7(44): 72242-72249.