Ligand-induced PPARγ activation has been shown to promote differentiation and to induce cell growth inhibition and apoptosis in several types of human cancer, including colon cancer (Sarraf et al, 1998; Kitamura et al, 1999; Yang and Frucht, 2001), breast cancer (Elstner et al, 1998; Mueller et al, 1998), lung cancer (Chang and Szabo, 2000), prostate cancer (Kubota et al, 1998; Butler et al, 2000), gastric cancer (Sato et al, 2000), liposarcoma (Tontonoz et al, 1997; Demetri et al, 1999), and leukaemia (Sugimura et al, 1999). This evidence concerns the gene PPARG and liposarcoma.