The VEGF receptors 1 and 2 (VEGFR1 and VEGFR2, respectively) were significantly up-regulated in later ARDS compared to normal subjects and early ARDS; this up-regulation of VEGFR1 and VEGFR2 in late ARDS suggests regulation of VEGF bioactivity by its receptors, assigning a protective role to VEGF in lung injury recovery [233]. This evidence concerns the gene VEGFA and acute respiratory distress syndrome.