TLR4 and sarcoidosis: HLA-DRB1*0301/ DQB1*0201 [34], transforming growth factor β (TGF-β) [35], tumor necrosis factor α (TNF-α) [36], and Toll-like receptor 4 (TLR-4) [37] are all considered significant indicators for susceptibility to sarcoidosis [38,39].