CCL2 and systemic sclerosis: The systems level analysis we performed on the DE genes in the intersection between IPF and SSc-PF was dominated by “immune response,” “collagen metabolism,” and “ECM organization” super clusters (Figure 3) and most of the query genes entered in the network were hit genes in “immune system processes” term, including hub proteins IL6, COL1A1, COL1A2, VCAM1, CXCL10, CXCL12, CCL2, CCL19, and FGG.