VEGFR-1 is abundantly expressed in TAMs, and blockade of VEGFR-1 signaling in obese but not lean mice leads to a shift in pro-tumor cytokine production and TAM polarization from an M2 pro-tumor to an M1 anti-tumor phenotype that ultimately reduce obesity-induced tumor progression [97]. This evidence concerns the gene FLT1 and obesity due to melanocortin 4 receptor deficiency.