This invention provides compositions and methods to treat a condition ordiseasewithout the use of exogenous targeting sequences or chemical compositions. Thepresentinvention relates to single-domain antibodies (sdAbs), proteins andpolypeptidescomprising the sdAbs that are directed against intracellular components thatcause acondition or disease. The invention also includes nucleic acids encoding thesdAbs,proteins and polypeptides, and compositions comprising the sdAbs. Theinventionincludes the use of the compositions, sdAbs, and nucleic acids encoding thesdAbs forprophylactic, therapeutic or diagnostic purposes.
