STING1 and systemic sclerosis: However, recently it was shown that patients with gain-of-function mutations in STING, a cytosolic DNA sensor, leading to constitutive expression of IFNβ, present with microvascular abnormalities similar to those observed in the nail-fold capillaries of SSc patients, namely nail-fold capillary tortuosity, capillary-loop loss, telangiectasia, and digital ulcers [15].