The HIV retrovirus, in particular, is a single-stranded RNA virus that duplicates itself in a host cell by converting its genetic code into double-stranded DNA that is then inserted into the host cell.

FORBES: Progress in Drug Therapy Marks the 25th Anniversary of World AIDS Day

Obama's move will be hailed by advocates for those suffering from a host of afflictions, ranging from diabetes to Parkinson's disease, who believe that an expansion of stem-cell research could boost medical progress toward eradicating the debilitating diseases.

CNN: Obama to reverse embryonic stem cell ban