reviews, myxoid liposarcoma was usually found to be low-grade and therefore relatively responsive to chemotherapy whereas high grade (i.e. round cell) myxoid lipsarcoma had higher rates of metastasis, behaved more aggressively, and did not respond well to chemotherapy. It is important to note, however, that almost all cases of myxoid liposarcomas in pediatric patients have had excellent prognoses. Novel therapies A PPAR-γ agonist (i.e. activator), efatutazone, was studied in a small phase I trial on individuals with various advanced-stage malignancies. The drug produced a markedly durable response in a person with MLS suggesting that PPAR-γ agonists would be useful for treating this disease. A stage II clinical trial conducted in Italy is examining the effects of a trabectedin plus pioglitazone (another PPAR-γ agonist) in individuals with stable MLS tumors. The study involves two sequential steps. The first step examines the response of patients treated for a minimum of 4 cycles with trabectedin alone. If stable disease is attained, the second step will examine the effects of further treating initially responding patients with a combination of trabectedin and pioglitazone. A stage II clinical trial is nearing completion to evaluate the efficacy of sirolimus (an inhibitor of MTOR; sirolimus is also known as rapamycin) plus cyclophosphamide (a chemotherapy drug) in metastatic or unresectable MLS. A phase II clinical trial is recruiting patients to evaluate sintilimab (a human IgG4 monoclonal antibody directed against the programmed cell death protein 1 located on the surface of cells) in combination with two chemotherapy drugs, doxorubicin and ifosfamide, as first-line treatment of soft tissue sarcomas including MLS. T cells have been genetically engineered to target the MAGE-A4 antigen expressed on a HLA-A*02 MAGE-A4-containing peptide located on the surface of the neoplastic cells in certain types of tumors. These engineered cells (termed ADP-A2M4-T cells) attacked and killed various cultured human cancer cells bearing this antigen and, in a clinical stage 1 study, shrank various solid tumor types in patients whose tumors' contained neoplastic cells expressing this antigen. A phase II clinical study is now recruiting individuals to investigate the efficacy and safety of ADP-A2M4 T cells (engineered from the recipient's own T cells) in HLA-A*02-positive patients with metastatic or inoperable, advanced-stage MSGE-4-positive MLS tumors. Pleomorphic liposarcoma Presentation Pleomorphic liposarcomas (PLS), which account for 5% to 10% of all liposarcoma cases, are fast-growing, usually large (>5 cm), and painless but highly malignant adipocyte tumors. They occur primarily in individuals