FN1 and systemic sclerosis: Interestingly, the only documented case of THBS-4 in SSc was recently published by Moon et al. The group applied a method of machine learning to mine a gene expression compendium of SSc patients and identified the genes THBS-1, THBS-4, THBS-5, FN1, and TN-C to best represent changes in the severity of skin fibrosis [111].