Having optimized conditions for TLR ligand-dependent cytokine secretion (Supplemental Fig. S1), IL-6, IL-11, TNF-α and IL-8 secretion was determined, 24-h after TLR ligand stimulation of primary Gingival Keratinocytes (PGK), pre-cancerous Dysplastic Oral Keratinocytes (DOK) and cancerous Oral Squamous Cell Carcinoma 4 Cells (SCC-4). Here, CXCL8 is linked to squamous cell carcinoma.