CX3CL1 was expressed on infiltrated mononuclear cells and endothelial cells in muscle affected by PM and DM and in lung with ILD, whereas CX3CR1 was expressed on some CD4+ T cells, a majority of CD8+ T cells, and most macrophages in muscle, and on infiltrated mononuclear cells in the lung. Here, CX3CR1 is linked to dermatomyositis.