TIM-3 is expressed at significantly higher levels in NPC cells than in nasopharyngeal epithelial cells, and TIM-3 can promote tumor progression in NPC by mediating epithelial-mesenchymal transfer of human signal transduction molecule 7 (SMAD7), SMAD2 and zinc finger transcription factor 1 (SNAIL1).[81]. This evidence concerns the gene SMAD2 and nasopharyngeal carcinoma.