COL18A1 and systemic sclerosis: Importantly, serum endostatin levels are increased in SSc patients and associated with the presence of skin sclerosis, giant capillaries in nailfold capillaroscopy, cardiovascular changes, and pulmonary vascular involvement [10]–[14], suggesting that CTSB contributes to the pathological processes associated with fibrosis and vasculopathy at least partially via modulating endostatin production.