Expression of L-selectin on T cells (fig 1C) was significantly lower in patients with SSc-PAH (26.4 (8)%) than in the HD group (75.5 (8)%, p<0.01) or in patients with SSc without PAH (75.5 (2)%, p<0.01), and gradually rose following bosentan treatment at the 6 months (43.1 (10)%, p<0.05 vs baseline) and 12 months controls (63.2 (6)%, p<0.01 vs baseline). Here, SELL is linked to systemic sclerosis.