  The adaptive immune system is a dynamical, self-organized multiscale system
that protects vertebrates from both pathogens and internal irregularities, such
as tumours. For these reason it fascinates physicists, yet the multitude of
different cells, molecules and sub-systems is often also petrifying. Despite
this complexity, as experiments on different scales of the adaptive immune
system become more quantitative, many physicists have made both theoretical and
experimental contributions that help predict the behaviour of ensembles of
cells and molecules that participate in an immune response. Here we review some
recent contributions with an emphasis on quantitative questions and
methodologies. We also provide a more general methods section that presents
some of the wide array of theoretical tools used in the field.
