ITGA4 and obesity due to melanocortin 4 receptor deficiency: To further elucidate whether obesity affected T cell trafficking, we measured the expression of the chemokine receptor CXCR3, which has been shown to mediate CD8 trafficking to tumors and the extravasation into the tumor tissue (Chamoto et al., 2017; Chheda et al., 2016; Mikucki et al., 2015), and the integrin CD49d on CD8 T cells, which is involved in T cell transmigration (Sökeland and Schumacher, 2019).