Compared with other cytokine-induced genes, such as the genes encoding tumor necrosis factor-α (TNF-α), interleukin (IL)-10, and IL-1β, the type I IFN signature in the blood is positively correlated with disease activity in individual patients with dermatomyositis (DM) or polymyositis (PM) during longitudinal follow-up according to a previous study (17). Here, TNF is linked to polymyositis.