HDAC9 and neoplasm: In contrast, overexpression is detected even in the absence of mutations, amplifications or CNVs, as has been described for other potential tumor markers including TFDP1 at the 13q34 locus [28] and NKX2-8[11] and NKX2-1[10] at the 14q13.3 locus, and as we demonstrated for the MEOX2, HDAC9, TWIST1 and AhR genes at the 7p21 locus.