TGFB1 and systemic sclerosis: However, the injection site of the SSc mouse is similar to the histologic features of human scleroderma skin, which show progressive skin thickening, excessive accumulation of collagen, immune cell infiltration, and thickening of the vascular wall, as well as to the cell biological characteristics, such as the fact that the number of mast cells grew steadily as the sclerotic alterations progressed, anti-nuclear antibodies were also detected in the serum of BLM-treated mice, and TGFβ1 mRNA was discovered at an early stage (32, 33).