A general role of ICPs as tumor suppressors within malignant cells is strengthened by the identification of a meta-gene expression signature composed of CD27, CEACAM1, CTLA-4, LRIG1, PD-L2 and GITR within a collection of tumor cell lines, which was also associated with a prolonged survival phenotypes in clinical specimens (36). Here, CEACAM1 is linked to neoplasm.