COL1A1 and idiopathic pulmonary fibrosis: Remarkably ΔRstiff/ΔRsoft of COL1A1 was ~2-fold higher in IPF-fibroblasts compared to control fibroblasts with statistical significance (Figure 6C), revealing an aberrant positive synergy between matrix stiffening and TGF-β1 in IPF-fibroblasts far beyond that of normal fibroblasts.