MAPK8 and rheumatoid arthritis: Studies using synovial lining fibroblasts (also called fibroblast-like synoviocytes) further revealed that HOXD10 expression is of critical importance for maintaining a quiescent fibroblast state as diseased fibroblast states (in rheumatoid arthritis), characterized by abnormal HOXD10 levels, impacted on increased cellular viabilities as well as abnormal migration via increased p38/c-Jun N-terminal kinase p38/JNK signaling (56).