RAG1 and obesity due to melanocortin 4 receptor deficiency: The B6.Rag1−/− model does, however, maintain macrophages with the capacity to recapitulate the pro‐inflammatory environment and oxidative stress induced by increased adiposity (Lee et al., 2011), and like its C57BL/6J background—the mouse strain most commonly used to study cancer and obesity (Donohoe et al., 2017)—B6.Rag1−/− presents a DIO phenotype that mimics human obesity (Boden et al., 2015; Collins et al., 2004; Lee et al., 2011; O'Neill et al., 2016; Zaytouni et al., 2017).