The Pearson correlation analysis between the expression of all 28 genes from Table 3 and miR-21 expression shows that within the five genes with an impact on the overall survival of HNSCC patients, four have positive correlations with miR-21 (ORL1, TGFBI, NETO2, and CDK6) (see Figure 5B). The gene discussed is OPRL1; the disease is head and neck squamous cell carcinoma.