SERPINF2 and obesity due to melanocortin 4 receptor deficiency: A recent study showed that Fgr kinase, a member of the Src kinase family, is required for the activation of proinflammatory macrophages during diet‐induced obesity.[44] Furthermore, Fgr has previously been reported to bind to Syk kinase and negatively regulate phagocytosis in murine macrophages.[20, 21] Here, we found that Api treatment could mitigate the binding of Fgr to Syk and promote the phosphorylation of Vav1.