In addition, to relatively compare our data to the previously published study by Alivernini et al. (30), we examined CD40 expression on MerTK+CD206+ synovial tissue macrophages and demonstrate that the high level of CD40 coexpression observed on CD206+CD163+ RA macrophages in our study is also present on MerTK+CD206+ synovial tissue macrophages in RA (fig. Here, MERTK is linked to rheumatoid arthritis.