There are several studies reported that the status of high TIICs may lead to poor prognosis41,42, which could be explained that some of the infiltrated immune cells, such as macrophages, would promote or result in tumor initiation, development and metastasis especially in the immunosuppressive microenvironment41,43, confirming our findings that TIGIT overexpression is related to the poor prognosis in certain cancers. Here, TIGIT is linked to cancer.