Another study of IS, which was the first to propose PDGFRA as a molecular hallmark for intimal sarcomas, found copy number gains of PDGFRA, EGFR, and MDM2 in 8 patients using FISH and aCGH with consistent activation of PDGFR and EGFR confirmed by western blotting [2]. This evidence concerns the gene MDM2 and intimal sarcoma.