Among the genes with CNAs, MDM2 and CDK4 were co-amplified...In addition to the co-amplification of MDM2 and CDK4, multiple gene amplifications were observed in chromosome 12q13-15 of the NCC-DDLPS4-C1 cell line...the HDAC inhibitor romidepsin showed equivalent to superior antiproliferative effects on NCC-DDLPS4-C1 cells....We also found that the HDAC inhibitor romidepsin has a remarkable antiproliferative effect on NCC-DDLPS4-C1 cells.