MDM2 and tumor of adipose tissue: MDM2 and chromosome 12 centromere (CEP12) using the Vysis LSI MDM2 Spectrum Orange Probe nd Vysis DNA FISH probe CEP12 (Abott Molecular/Vysis, Des Plaines, IL, USA) were examined, and.[13] results of MDM2-FISH showed focally positive and 5.96 of MDM2/CEP12 ratio, suggesting that MDM2 gene amplification indicated the lipomatous tumor as WDLS.