TAT and infection: A potential leaky Tat mRNA expression could also be responsible for diluting strong signatures in the model [18] Nevertheless, the mouse model tested here allows a rigorous systems-based analysis of the effects of upregulation of the Tat protein, although excluded from active infection, and proposes a model on how it can act in vivo on modulating suppressive patterns of transcription changes that are caused by comorbidities such as Meth.