We have previously shown that adenosine promotes fibrogenesis in the skin in vivo [9], that A2AR blockade prevents scarring in vivo [5] and activation of the adenosine A2A receptor but not A1 or A2B receptors promotes dermal extracellular matrix protein production including type I collagen in primary human dermal fibroblasts, and in a murine model of scleroderma [6]. This evidence concerns the gene ADORA2A and scleroderma.