Previous studies revealed that there was an increased amount of M1 macrophages, which can secrete IL-6 and TNF-alpha to induce an inflammatory reaction, in the blood of BD patients, while the amount of macrophage M2, which has anti-inflammatory characteristics, was reduced in the blood of BD patients, further inducing the inflammatory reaction in these patients (Nakano et al., 2018; Shi et al., 2019; Hirahara et al., 2022). Here, IL6 is linked to Behcet disease.