Results showed significantly higher level of HSP90 beta (2.7 fold) in serum samples of HNSCC (65.6±13.08 ng/ml) compared to HC (23.5±3.8 ng/ml) with a P value of 0.002 (Fig 1A & Table 2). However, the levels of HSP90 alpha did not show significant difference between the HNSCC and HC (S1 Fig). This evidence concerns the gene HSP90AB1 and head and neck squamous cell carcinoma.