ATM and systemic sclerosis: A different cell cluster gene expression profile between ATA+ and ARA+ SSc patients was subsequently confirmed by the same group through sc-RNAseq on SSc skin, with transforming growth factor β (TGFβ) ligand-receptor interactions occurring mainly in fibroblasts and smooth muscle cells in early ATA+ dcSSc patients, while mostly in endothelial cells in early ARA+ dcSSc individuals [32▪].