<P> MHC class II molecules are a class of major histocompatibility complex (MHC) molecules normally found only on antigen - presenting cells such as dendritic cells, mononuclear phagocytes, some endothelial cells, thymic epithelial cells, and B cells . These cells are important in initiating immune responses . </P> <P> The antigens presented by class II peptides are derived from extracellular proteins (not cytosolic as in MHC class I). </P>

Where are class ii mhc found and what cells recognize them