THBD and systemic sclerosis: Disease-specific associations were found with certain cell types in the blood, spleen, lung, and small intestine, such as CD141-positive myeloid dendritic cells with SSc and erythrocytes in the spleen with SLE (Figure 4 and eFigure 19 in Supplement 1), which may be an important triggering source of type I interferon disturbance in SLE.