A study identifies the endogenous VEGF-A splice variant VEGF165b as an endogenous shield against inflammatory vascular leak in acute lung injury and acute respiratory distress syndrome. By characterizing how this splice variant protects lung blood vessels, the research points to a biology-driven target mechanism distinct from current broad anti-inflammatory approaches. If validated in translational models, VEGF165b biology could inform therapeutic design aimed at stabilizing the pulmonary microvasculature during severe inflammation.