CCL8 and immunoglobulin G4-related sclerosing disease: confirmed that blocking CCL8 (analog of human CCL18) in LATY136F knock-in mice (an animal model of IgG4-RD) alleviated the degree of fibrosis in affected salivary glands, and further in vitro assays revealed that CCL8 could directly stimulate collagen production in mouse fibroblasts (17).