TGFB1 and systemic sclerosis: A mouse strain that replicates many aspects of SSc is the transgenic strain that has expression of a nonsignaling type 2 TGFbeta receptor on fibroblasts.[16] This leads to an imbalance of signalling TGFbeta receptors and ligand dependent TGFbeta pathway activation.[17] Mice are prone to excess fibrosis in response to minor tissue injury and this is relevant to the lung.