PTGDS and Graves disease: PGD2 and 15d-PGJ2 are also agonists of PPARγ and can induce differentiation of fibroblasts to adipocytes; this has been shown in the case of Grave’s disease where it was reported that activated T cells drive fibroblast differentiation in ocular tissue through production of PGD2 and 15d-PGJ2, implying that T cell infiltrates can influence fat deposition in other tissues (67).