HDAC9 and testicular germ cell tumor: Our data on 261 TGCT tumor components, together with the in silico analysis of the TCGA database (156 samples) [45] constitutes the largest series reported thus far in which HDACs expression was analyzed, and confirms the differential expression of members of the various HDAC families among TGCT subtypes, indicating a distinctive role in the biology of SEs and, particularly, of NSs, in which most isoforms are upregulated.