CCL17 and nasopharyngeal carcinoma: DEG analysis revealed that Treg_C1_SELL had high expression of chemokine receptors CCR4, which are chemotactic counterparts for CCL5, CCL17, and CCL22 produced by intratumoral CD8+ T, NK, and myeloid cells in NPC (Supplementary Figs. 5a and 6c).