MHC1 and 2
As described in the introductory module, all nucleated cells contain MHC I on their cell surface. An important exception to this rule are platelets. Although platelets do not have a nucleus, they do express MHC I molecules on their cell surface. MHC I molecules process and present endogenous, or intracellular antigens. MHC II molecules, found on antigen presenting cells, process and present exogenous, or extracellular antigens.
