Sitagliptin, a widely used drug for the treatment of type 2 diabetes, has been shown to promote macrophage polarization towards the M2 phenotype via chemokine stromal cell-derived factor-1/C-X-C chemokine receptor type 1 (SDF-2/CXCR1) signaling, thereby attenuating early atherosclerotic lesion formation (80). The gene discussed is CXCR1; the disease is type 2 diabetes mellitus.