3-Deazaadenosine HCl (3-DZA, c3Ado) is a potent inhibitor of S-adenosylhomocysteine hydrolase with Ki of 3.9 µM. 3-Deazaadenosine HCl inhibits bacterial lipopolysaccharide-induced transcription of TNF-α and IL-1β. 3-Deazaadenosine HCl inhibits the transcriptional activity of NF-κB, prevents FCS-induced Ras carboxyl methylation and reduces FCS-induced ERK1/2 and Akt phosphorylation. 3-Deazaadenosine HCl has anti-inflammatory, anti-proliferative and anti-HIV activities.