At the whole-body scale, systems pharmacology models by Chu et al (92) and Clegg et al (93) revealed how various pro-angiogenic and anti-angiogenic VEGF isoforms (VEGF165a and VEGF165b) are differentially distributed within body compartments (eg, blood, calf muscle) in PAD as well as the resulting impact on downstream proliferative signaling in muscle. The gene discussed is VEGFA; the disease is peripheral arterial disease.