Preliminary findings using peripheral blood mononuclear cells (PBMC) or Jurkat cells infected with HIV-1 or HIV-2 indicated that HIV-1 infection generated more reactive oxygen species (ROS), increased the expression of a larger number of molecules involved in cell signaling such as p47, p38α, c-Jun N-terminal kinases (JNK), c-Yes, total protein kinase C (PKC), and decreased the expression of molecules such as p38β, extracellular receptor kinases (ERK)1/2, X-linked inhibitor of apoptosis protein (XIAP) leading to increased cell death by apoptosis relative to HIV-2 infection. This evidence concerns the gene XIAP and HIV-1 infection.