Several retroviruses use reverse transcriptase to replicate their genomes, which is central to their infectious nature. Some of the more common viruses that use reverse transcriptase include:

• Human immunodeficiency virus (HIV), which causes acquired immunodeficiency syndrome (AIDS)
• Hepatitis B virus (HBV), which causes a potentially life-threatening liver infection
• Human T-cell lymphotropic virus I (HTLV-I), which causes leukemia