In contrast to GM-CSF, which has been reported to support wound angiogenesis26, the NK cell-derived cytokine IFN-γ exerts a strong, direct antiangiogenic function on endothelial cells10,27, thus reduced IFN-γ levels in wounds and GAS lesions likely contribute to enhanced vascular remodelling in HIF-1α KO mice. The gene discussed is HIF1A; the disease is flatulence.