Exosomes are implicated in the induction of immune escape mechanisms in tumor cells, such as the evasion of immunogenic cell death through damage-associated molecular patterns (DAMPs) and the expression of surface recognition molecules including CD39/CD73, CD38, CD47, cytotoxic T-lymphocyte antigen 4 (CTLA-4, also known as CD152), lymphocyte-activation gene 3 (LAG-3), V-domain immunoglobulin suppressor of T cell activation (VISTA), and T cell immunoglobulin and mucin domain 3 (TIM-3) (Zhang et al., 2015; Wo et al., 2019). The gene discussed is CTLA4; the disease is neoplasm.