In the present study, we have analyzed the expression and activity of SIRT1 and SIRT2 in the most common pediatric soft tissue sarcomas, rhabdomyosarcoma and synovial sarcoma can be of two histological subtypes; the embryonal subtype (ERMS) is genetically characterized by the loss of the short arm of chromosome 11. The gene discussed is SIRT1; the disease is synovial sarcoma.