CCR1 and Oral ulcer: In Behçet’s disease (BD) patients with oral ulcers, the oral microbiota seems to lead to the excessive persistence of inflammation by inducing the abnormal polarization of M1/M2, which is related to the reduction of CCR1 of M2 in BD patients, with CCR1 attenuating the chemotaxis effect of M2 on MIP-1α and decreasing the expression of IL-10.