IL6 and systemic sclerosis: The inactivation of monocyte-macrophage lineage cells in parallel of skin fibrosis resolution, which is commonly seen in SSc patients treated with tocilizumab and fresolimumab, strongly suggest the crucial role of monocyte-macrophage lineage cells and the involvement of IL-6 and TGF-β in the activation of those cells during the fibrotic process of this disease.