Antibodies against the PM-Scl complex are associated with the scleroderma/polymyositis overlap syndrome. These antibodies usually coexist with positive antinuclear antibodies (ANA) with nucleolus type of fluorescence. Antibodies against the complex may be directed to different subunits in the PM-Scl complex, usually the 75 kDa and 100 kDa subunits. The presence of antibodies against the PM-Scl complex is often associated with Raynaud's phenomenon, arthritis, muscle aches, and disorders of the skin and lungs.