HDGF and head and neck cancer: According to TCGA data analysis (n = 522, oral cancer; n = 566, head and neck cancer [TCGA, Provisional cohort]), the HDGF and VEGF mRNA expression profile exhibited a strong positive correlation (P = 0.0107; R2 = 0.01247, oral cancer; P = 0.0001; R2 = 0.02643, head and neck cancer) (Fig. 1A and B).