PPARG and neoplasm: Furthermore, GDF15 is a known p53-induced gene following treatment with NSAID, PPARγ ligands and chemotoxic reagents like etoposid and doxorubicin resulting in a proapoptotic phenotype.18,20,33 This suggests, that the absence of GDF15 induction in the platinum-resistant tumor model A2780cis may indicate a decreased apoptosis response following carboplatin treatment.