It has also been reported by others that high PDPN expression is associated with aggressive tumor behavior, poor prognosis and metastatic regulation through interaction with VEGF-C, suggesting that PDPN may be used as a potential prognostic biomarker for HNSCC.27 However, our in vitro studies did not reveal increased PDPN expression in HNSCC cells that resisted to MI (Supplementary Figure S8). This evidence concerns the gene VEGFC and head and neck squamous cell carcinoma.