During the process, low oxygen tension (hypoxia) is a significantly important component of the TME driving tumor angiogenesis, which could upregulate multifarious proangiogenic growth factors like VEGF, placenta growth factor (PlGF), and angiopoietin 2 (Ang2) that correlate with the formation of new vessels through directly engaging in vessel growth (94, 95). The gene discussed is PGF; the disease is neoplasm.