HPGD and head and neck squamous cell carcinoma: Among these 53 microRNA-mRNA pairs tested, 4 exhibited apparent inverse correlations in both OTSCC tissue samples and HNSCC cell lines (miR-21-GPD1L, miR-21-HLF, miR-21-HPGD and miR-130b-MGLL, with Pearson’s correlation coefficient r = −0.6784, −0.7801, −0.55, −0.6913 for OTSCC tissue samples, and r = −0.4509, −0.5774, −0.5841, and −0.5158 for HNSCC cell lines, respectively).