TNF and Atrophy: RSV has also been shown to upregulate the phosphorylation of protein kinase B (Akt), p70 ribosomal S6 protein kinase (p70S6K), mammalian target of rapamycin (mTOR), and eukaryotic translation initiation factor 4E- (eIF4E-) binding protein 1 (4E-BP1) in TNF-α-induced atrophy [5].