Gag assembly leads to formation of the immature lattice. The Gag molecules in the immature virion are extended and oriented radially, with their amino-terminal MA domains bound to the inner membrane leaflet and their carboxy- terminal p6 domains facing the interior of the particle. The GAGPol Pro molecules have arrived at the site of viral assembly in fewer numbers than the Gag protein (20:1). The trimeric gp41:gp120 complex is brought to the plasma membrane by the host vesicular transport system. Only 7-14 trimers per virion. VPU has followed the same ER:Golgi path. Vif, Nef, and Vpr are packaged along with the the HIV genome.