EGLN1 and head and neck squamous cell carcinoma: On the other hand, downregulation of PHD2 showed an antitumor effect in GBM,148,150 head and neck squamous cell carcinoma,151 and bone marrow-derived cells.152 Considering the significance of PHD2 in tumor progression and HIF regulation, PHD2 could be a potential therapeutic target in the treatment of GBM and other cancer types.