CXCL1 and obesity due to melanocortin 4 receptor deficiency: The secretion of multiple pro-inflammatory cytokines and chemokines (such as CXCL1) gives rise to the accumulation of M1 macrophages in adipose tissues, leading to insulin resistance and obesity (Barra et al., 2010; McGillicuddy et al., 2011; Chang et al., 2012; Kawano et al., 2016).