IL6 and oral cavity squamous cell carcinoma: OSCC: Oral squamous cell carcinoma; WDSCC: well-differentiated squamous cell carcinoma; MDSCC: moderately differentiated squamous cell carcinoma; PDSCC: poorly differentiated squamous cell carcinoma; IL-6: Interleukin-6; PG/ML- Picograms/Milliliter