Moreover, there were significant correlations between VEGF-A and VEGF-C in both adenocarcinoma (Pearson correlation r = 0.439, p < 0.001) and squamous cell carcinoma (Pearson correlation r = 0.574, p < 0.001) (Additional file 2: Fig. S2, S3). This evidence concerns the gene VEGFA and adenocarcinoma.