Moreover, azithromycin extremely decreased the mRNA levels of IL-1β, IL-6, and TNF-α in SLE macrophages (0.22 ± 0.20 fold change, p = 0.000, 0.13 ± 0.17 fold change, p = 0.000, 0.20 ± 0.11 fold change, p = 0.000), while the mRNA levels of Arg-1, Fizz-1 (p = 0.0005), and IL-10 (p = 0.002) significantly increased after azithromycin treatment (Fig. 3b). Here, RETNLB is linked to systemic lupus erythematosus.