IFIH1 and dermatomyositis: This is the case for anti–TIF1-γ–positive dermatomyositis (DM) patients, who typically present with clinical erythroderma and extensive psoriasiform and hyperkeratotic plaques, as well as for anti–MDA5–positive DM patients, who often develop necrotic cutaneous ulcers, telangiectasias, poikiloderma, and diffuse interstitial lung disease (ILD).