Disjointed: Cell differences may explain why rheumatoid arthritis varies by location

Researchers at the University of California San Diego School of Medicine, with colleagues in Pennsylvania and China, report that not only are there distinct differences in key cellular processes and molecular signatures between rheumatoid arthritis (RA) and osteoarthritis (OA) but, more surprisingly, there are joint-specific differences in RA. The findings help explain, in part, why drugs treating RA vary in effect—why, for example, a treatment that might work in arthritic knees isn't effe