This MAb [D33] recognizes desmin antibody, a 53kDa intermediate filament (IF) protein. Studies have shown that [D33] is highly specific to desmin and shows no cross-reaction with other IF proteins. Studies have also shown D33 to be useful in identification of tumors of myogenic origin; it has been shown to react with leiomyosarcomas (smooth muscle) as well as rhabdomyosarcomas (striated muscle). Several studies have utilized desmin in a panel to aid in the classification of uterine sarcomas. Studies addressing desmoplastic reaction in colorectal and pancreatic cancers have demonstrated D33 to be a helpful marker of tumor invasion.