FCGR2B and pulmonary edema: AAV-sh-Elk1 treatment upregulated the PaO2/FiO2 ratio and alleviated pulmonary edema, whereas AAV-sh-Elk1 and AAV-sh-Fcgr2b treatments diminished the PaO2/FiO2 ratio and exacerbated pulmonary edema (Fig. 6F-G).