Given that survivin functions as an anti-apoptosis protein, we evaluated the sensitivity of hASCs to apoptosis induced by hypoxia and leptin, two recognized obesity-related apoptotic stimuli in AT.33, 34, 35 As anticipated, basal apoptosis was not significantly different between obese- and lean-isolated hASCs cells (Figure 4a), as previously reported.30 Both hypoxia and leptin significantly increased the number of apoptotic cells in lean- but not in obese-derived hASCs, as detected by double staining with annexin V and propidium iodide (Figure 4a). Here, LEP is linked to obesity due to melanocortin 4 receptor deficiency.