CD4 and obesity due to melanocortin 4 receptor deficiency: Obesity induced by HFD increased the CD8+/CD4+ ratio (p = 0.020), while reducing the population of CD4+ T cells (p = 0.027) and of Foxp3+ Tregs (p = 0.001) within the CD3+ CD4+ T cell population in adipose tissue compared to the SD (Fig 2a–2c).