Glycoprotein gp120 is encoded by env, and is exposed on the surface of the viral envelope. It binds to the CD4 receptor on any target cell that has such a receptor, particularly the helper T-cell. It is formed by cleavage of gp160.
p17 and p24 are proteins are encoded by the gag gene, and provide structural elements of the virus.
has not yet been referenced specifically in any publications.