Yamashita K, Kohashi K, Yamada Y, et al. - Researchers sought to report on the progression process and to ascertain the pathological and genetic factors linked with poor prognosis in dedifferentiated liposarcoma (DDLPS). They analyzed genetic factors in 32 DDLPS cases and five well‐differentiated liposarcoma (WDLPS) cases using custom comparative genomic hybridization (CGH) array, which was meant to densely cover gene regions known to be frequently amplified in WD/DDLPS. Intra‐tumoral genetic heterogeneity and progression were identified in the analyses comparing primary and metastatic lesions and those comparing histologically different areas in the same tumor. MDM2 and HMGA2 were selected as candidate genes linked with poor and good prognosis, respectively, in prognostic analysis comparing the good‐prognosis and the poor‐prognosis groups. Prognosis was noted to be significantly linked with ratios of the amplification or gain levels of MDM2 and HMGA2 expressed in log ratios (log[MDM2/HMGA2] = log[MDM2]‐log[HMGA2]). Strong correlation of an amplification or gain level of MDM2 that was more than twice that of HMGA2 (MDM2/HMGA2 > 2, log[MDM2/HMGA2] > 1) was observed with poor OS and poor distant metastasis‐free survival (DMFS). Further, there was association of cellular atypia with DMFS.