HIF1A and neoplasm: In other studies for cancer immunotherapy, a pH-sensitive cationic lipid nanoparticle was used to deliver siRNA to TAMs and achieve anti-tumor therapeutic response by silencing the STAT3 and HIF-1α, which increased infiltrated macrophages (CD11b+/− cells) in the TME as well as the density of M1 macrophages (CD169+/− cells), thus resulting in reversing the pro-tumorous functions of TAMs-mainly angiogenesis and tumor cell activation [245].