Coculturing of TAMs and pancreatic cancer cells or culturing oral squamous cell carcinoma in an M2 macrophage-derived conditioned medium promotes their expression of stemness-related genes.249,250 Conditioned medium from TAMs promotes stemness of lung cancer cells by upregulating Ubiquitin-Specific Peptidase 17 (USP17), which subsequently disrupts the TNFR-Associated Factor (TRAF) 2/TRAF3 complex.251 These results suggest that the secretomes of TAM are essential in the process. This evidence concerns the gene USP17L9P and oral cavity squamous cell carcinoma.