In this study, we analyzed the expression levels of the mCCL8 (analog of hCCL18)–CCR8 axis in LAT mice as a murine model of IgG4-RD and injected the mice with anti-mCCL8 antibody to explore whether mCCL8-blocking therapy would reduce the development of tissue lesions, especially in sialadenitis, in which the elevated expression of hCCL18 has already been demonstrated in human IgG4-RD. Here, CCR8 is linked to sialadenitis.