CD4 and obesity due to melanocortin 4 receptor deficiency: In participants with class 1 and 2 obesity, we found positive correlations between the percentage of CD3+ T lymphocytes and age (Fig. 3A), between the percentage of CD8+CD45RO+ T lymphocytes and WC (Fig. 3B), and between the percentage of CD4+CD45RO+ T lymphocytes and FFM (Fig. 3C), and a negative correlation between CD4+CD45RA+ T lymphocytes and FFM (Fig. 3D).