CD28 and adult T-cell leukemia/lymphoma: Genetic analyses of adult T-cell leukaemia/lymphoma (ATLL) have revealed novel events that highlight the importance of immune evasion including CTLA4::CD28 and ICOS::CD28 fusions, REL C-terminal truncations [215, 216], recurrent alterations in HLA-A and HLA-B and structural variations disrupting the 3′-untranslated region of CD274 (PD-L1) [217].