With the purpose to decode the mechanism of miR-18a from M2 macrophages in NPC cell cycle distribution and apoptosis, M2 macrophages transfected with miR-18a mimics, miR-18a inhibitors, si-TGFBR3, or OE-TGFBR3 were co-cultured with SUNE-1 cells or CNE2 cells in the Transwell chamber. Here, TGFBR3 is linked to nasopharyngeal carcinoma.