Human interferon alpha 2a (hIFNα2a) is a cytokine that has been used in hepatitis and cancer treatments. It has wide biological potency covering antiviral, antiproliferative and immunomodulative activities. In addition, hIFNα2a regulates many genes as responses to virus, bacteria, antigen or mitogen exposures. This mini review discussing hIFNα2a as therapeutic protein that focuses on its molecular characteristic, molecular mechanism and production process. The development of prominent commercial product describes its manufacturing, preclinical and clinical studies, therapeutic efficacy as well as development possibility in the future.