Not to be confused with group presentation. Representation theory is a branch of mathematics that studies abstract algebraic structures by representing their elements as linear transformations of vector spaces, and studies modules over these abstract algebraic structures.
The signature effect of HIV infection, and the cause of AIDS, is disruption of the T-lymphocyte branch of the immune system and in particular the destruction of CD4+ T-helper cells.
HIV can infect and kill many different types of cells in the body but the primary targets are the CD4 T-cells, which are white blood cells that helps coordinate the immune system's response to infections and diseases.