The administration of bleomycin induced the reduction of PECAM1 expression (Fig. 2a, b) and blood flow (Fig. 2c) in the skin of SSc model mice, and the blocking of α2AP by α2AP-neutralizing antibodies improved the bleomycin-induced reduction of PECAM1 expression within the dermis (Fig. 2a, b) and blood flow (Fig. 2c) in the skin of SSc model mice. This evidence concerns the gene SERPINF2 and systemic sclerosis.