In the context of fibrotic disease, the gp38 marker has been reported to be expressed in CD34−gp38+CD90+ reticular cells in the skin of the patients with systemic sclerosis and in mouse skin wounds (25) as well as a subset of ADAM12+gp38+PDGFRα+ in skin and muscle acute injury stromal cells (5). Here, PDPN is linked to systemic sclerosis.