EGLN1 and head and neck squamous cell carcinoma: On the one hand, PHD2 promotes metastasis through activation of CAFs and inactive PHD2 inhibits proliferation and growth in breast cancer [82], stroma and bone marrow-derived cells [83], lung carcinoma [84], B-cell lymphomas [85], hepatocellular carcinoma [86], and head and neck squamous cell carcinoma [87].