For example, env codes for a protein called gp160 that is cut in two by a cellular protease to form gp120 and gp41.
Without treatment, average survival time after infection with HIV is estimated to be 9 to 11 years, depending on the HIV subtype.
In most cases, HIV is a sexually transmitted infection and occurs by contact with or transfer of blood, pre-ejaculate, semen, and vaginal fluids.
Regions in the LTR act as switches to control production of new viruses and can be triggered by proteins from either HIV or the host cell.
The Psi element is involved in viral genome packaging and recognized by Gag and Rev proteins.
Non-sexual transmission can occur from an infected mother to her infant through breast milk.