B7x (B7 homolog x, also known as B7-H4, B7S1, and VTCN1) was discovered by ourselves and others in 2003 as the seventh member of the B7 family. It is an inhibitory immune checkpoint of great significance to human disease. Tissue-expressed B7x minimizes autoimmune and inflammatory responses. It is overexpressed in a broad spectrum of human cancers, where it suppresses antitumor immunity. Further, B7x and PD-L1 tend to have mutually exclusive expression in cancer cells. Therapeutics targeting B7x are effective in animal models of cancers and autoimmune disorders, and early-phase clinical trials are underway to determine the efficacy and safety of targeting B7x in human diseases. It took 15 years moving from the discovery of B7x to clinical trials. Further studies will be necessary to identify its receptors, reveal its physiological functions in organs, and combine therapies targeting B7x with other treatments.

中文翻译：

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B7x免疫检查点途径：从发现到临床试验。

B7x（B7同系物x，也称为B7-H4，B7S1和VTCN1）是我们本人和其他人于2003年发现的，是B7家族的第七个成员。它是对人类疾病具有重要意义的抑制性免疫检查点。组织表达的B7x可将自身免疫和炎症反应降至最低。它在广泛的人类癌症中过表达，在这些癌症中它会抑制抗肿瘤免疫力。此外，B7x和PD-L1倾向于在癌细胞中具有互斥表达。针对B7x的治疗剂在癌症和自身免疫性疾病的动物模型中有效，并且正在进行早期临床试验以确定针对B7x的人类疾病的疗效和安全性。从发现B7x到临床试验花了15年的时间。有必要进行进一步的研究以鉴定其受体，