In tongue SCC, methylation levels at CpG2 and CpG3 were significantly correlated with mRNA levels (Spearman correlation coefficient rho = −0.738 (CpG2) and −0.769 (CpG3), P = 0.000) (Fig. 3b), whereas in tonsillar SCC OAS2 hypomethylation at CpG2 and 3 was not correlated with gene overexpression (Fig. 3c). Here, OAS2 is linked to tongue squamous cell carcinoma.