ATM and Ataxia: Overall, the novel transcriptome profile of 12-month-old ATM-null cerebellum has shed light on the primary role of osmotic stress in A-T pathogenesis, identified molecular correlates of A-T phenotypes such as incipient ataxia/vasodilatation/growth impairment, defined dysregulations of interactor molecules of cytosolic ATM that may represent useful upstream targets of neuroprotection, and documented generalised affection of neurotransmission and neuropeptide signalling—presumably mediated by cytoplasmic vesicles that have ATM protein associated to them.