Given that the expression of CD39 is related to the suppressive activity of both CD4 and CD8 Treg cells (4, 7), its expression was analyzed on freshly isolated CD8+CD28− (formally CD8+ Treg precursors) and on in vitro-generated CD8+ Treg cells from both SSc patients and healthy donors. Here, ENTPD1 is linked to systemic sclerosis.