CCL15 and nasopharyngeal carcinoma: This suggests that CCR1, CCR4 and/or CCR5+CD8+ T cells have seen antigens and/or are triggered by chemo-attractant ligands, which would be in line with the observed higher pre-treatment levels of CCL14 and CCL15 in the plasma of non-recurrent NPC patients (Cohort 2) [40].