CD4 and nasopharyngeal carcinoma: Compared with the HC group, the NPC group had a significantly larger number of PD‐1+ T cells (both CD4 and CD8) and PD‐1+ NKT cells (both CD4 and CD8; p ≤ 0.0001 [PD‐1+ CD4 T], 0.0010 [PD‐1+ CD8 T], 0.0002 [PD‐1+ CD4 NKT] and 0.0060 [PD‐1+ CD8 NKT], Figure 3C).