Although it was not statistically significant in the difference of relative mRNA expression in PBMCs between SSc patients and SSc-PAH patients due to limited samples, there was a trend that the mRNA expression levels of IFIT2, IFIT3, RSAD2, and PARP14 in PBMCs from SSc-PAH patients were higher than that from SSc patients. Here, IFIT3 is linked to systemic sclerosis.