Sporaic inclusion body myositis (sIBM) is an inflammatory muscle disease, characterized by slowly progressive weakness and wasting of the distal and proximal muscles, most apparent in the muscles of the arms and legs. In sporadic inclusion body myositis [MY-oh-sigh-tis] muscle, two processes, one autoimmune and the other degenerative, appear to occur in the muscle cells in parallel. The inflammation aspect is characterized by the cloning of T cells that appear to be driven by specific antigens to invade muscle fibers. The degeneration aspect is characterized by the appearance of holes in the muscle cell (vacuole)s, deposits of amyloid-related proteins within the cells and filamentous inclusions (hence the name inclusion body myositis) of abnormal proteins.