DDR2 and dedifferentiated liposarcoma: In recent years, an increasing number of whole-genome sequencing studies have identified that additional gene amplifications within the 12q13-15 region in WDLPS/DDLPS (such as the amplification of HMGA2, TSPAN31, FRS2, GLI1, YEATS4, YEATS2, NAV3, and CPM in WDLPS), new genes outside the 12q13-15 region (such as DDR2 and SDHC in WDLPS, and FGFR3 in DDLPS), and receptor tyrosine kinase (RTK)-related signaling pathways are closely associated with the occurrence and progression of WDLPS/DDLPS (10–12).