Ohta et al (2001) studied the expression of PPARγ in papillary thyroid carcinoma (PTC) cell lines and in thyroid tumours. They showed that most cell lines and half of PTCs expressed PPARγ, while normal adjacent tissue and two FTAs were negative. This group as well as Martelli et al (2002) also demonstrated that PPARγ agonists induce apoptosis and inhibit the growth of thyroid tumour cells. This evidence concerns the gene PPARG and differentiated thyroid carcinoma.