Translucent cutaway models of HIV showing part of the matrix protein shell (blue), and the viral core (pink). The core contains the viral genetic material (RNA - glows orange). The virus is covered by an envelope (translucent green) derived from the host cell during budding. Some of the spikes that the virus uses to attach to target cells are shown. The background is a complex texture at bottom fading to black at the top. The viruses are shown very close in which creates an almost abstract pattern, especially seen in the golden knobs which seem to swirl around the virus particles.