From the authors

We would like to thank N.M. Siafakas and I. Mitrouska for their insightful comments about our recent article published in the European Respiratory Journal 1. They suggest that resistive breathing may be a potent stimulus for upregulation of angiogenesis-promoting factors within the diaphragm. Preliminary data (which have appeared only in abstract form) suggest that resistive breathing might lead to an upregulation of vascular endothelial growth factor (VEGF), but not basic fibroblast growth factor (bFGF) and transforming growth factor-b1 …