Doses of 125, 250, 500 nM of EGCG for 24 h also demonstrated anti-RA effects on human rheumatoid arthritis synovial fibroblasts (RASFs) via suppression of mitogen-activated protein kinase (MAPK), MMP-1, MMP-3, p-extracellular regulated kinases (ERK)1/2, p-JNK, p-p38, and AP-1 formation [31]. Here, MAPK8 is linked to rheumatoid arthritis.