PTTG1 is a securin that regulates sister chromatin separation during mitosis, and it plays a role in DNA repair, metabolism, senescence, apoptosis and gene transcription.33, 34PTTG1 is also a prognostic marker in human ACCs,13, 35 as well as in other tumour types in humans and dogs.36, 37, 38 Several drugs have been shown to inhibit PTTG1 expression, including BRAF, HDAC, Hsp90 and STAT3 inhibitors,39, 40, 41 which could be interesting options to target PTTG1 in canine ACTs. Here, HDAC9 is linked to neoplasm.