After a century of careful investigation into the genetics,
genomics, biochemistry, cell biology and cellular immunology of
the adaptive immune response, there is a clear picture of antigen
processing and the subsequent antigen presentation by major
histocompatibility complex (MHC) class I and class II molecules
to T lymphocytes and natural killer (NK) cells. However, almost
all of this work has focused on a few mammals important for
biomedicine: humans, mice and to a lesser extent rats. To what
extent are the pictures found in textbooks true for the other animals?