Treatment of tumor cellswith romidepsin did not reduce HDAC1 and HDAC2 activities.49 Another study is contrary to this finding anddemonstrates a significant decrease in HDAC1/2 activity after romidepsintreatment.50 In our study, treatment oftumor cells with romidepsin and MS-275 did not reduce HDAC1 activities,especially in TFK-1 cells, whereas HDAC2 activity was reduced in EGI-1cells. This evidence concerns the gene HDAC1 and neoplasm.