In rheumatoid arthritis, the immune system attacks the synovial membrane of the synovium. If left untreated, there is a risk of gradual joint destruction. DMARDs are therefore used in severe courses. Omics analyses of individual cell types provide new insights into disease progression. Among other things, the focus is on research into T-cell activity and different types of tissue macrophages as a basis for new treatment strategies. Current findings and study results were reported at the annual meeting of the German Society of Rheumatology (DGRh).