Of note, focusing on SSc-ILD alveoli, which were the compartment characterized by a higher presence of macrophage infiltrate (CD68+cells), there was a significant overlap between CD68+, CD204+, CD163+, CD206+ and TLR4+cells, revealing the likely the presence of TLR4+M2 macrophages. This evidence concerns the gene TLR4 and interstitial lung disease.