The correct names for CT4 and CT8 cells are CD4+ T cells and CD8+ T cells. 1. CD4+ T-cells are the main target cells of HIV (Human Immunodeficiency Virus) infection and are themselves the central cells of the immune response, playing an important role in the body’s immune response. CD4 cell determination in the blood is an important indicator of the body’s immune function. 2. CD8+ T cells originate in the bone marrow and develop in the thymus. Once activated, they undergo a cascade of replication and differentiation, resulting in a directed immune response; apoptosis is induced by means of perforin and granzyme. CD4 and CD8 molecules interact with MHC (histocompatibility complex) class II and class I molecules, respectively, and are able to enhance interactions between T cells and antigen-presenting or target cells and participate in T cell activation signaling. For specific knowledge, consult a hematologist.