IL2 and rheumatoid arthritis: In RA, the unique top canonical pathways included Regulation of IL-2 expression in activated and anergic T lymphocytes, Th1 and Th2 activation pathways, T cell receptor signaling, PKCθ signaling in T lymphocytes, Calcium-induced T lymphocyte apoptosis and OX40 signaling pathways reflecting pathogenic role of T cell response.