CTLA4 and cancer: Other exosomal proteins have also been identified as important predictive biomarkers of GIC owing to create cancer-friendly condition to promote cancer metastasis, like exosomal Formin-like 2 (FMNL2), cytotoxic T lymphocyte antigen 4 (CTLA-4), RAB5A, aspartate β-hydroxylase, and so on [84–90].