CTLA4 and nasopharyngeal carcinoma: Lymphocyte activation gene 3 (LAG-3) and Hepatitis A virus cellular receptor 2 (HAVCR2) were also observed to be key immune checkpoint molecules in dysfunctional CD8+ T cells (138) while Cytotoxic T-lymphocyte-associated protein 4 (CTLA4+) FOXP3+ Tregs enrichment in EBV-positive NPC also highlights other immune checkpoint pathways.