Underlying all immune responses are the developmental programs
that give immune cells their identities. Developmental
controls determine the kinds of effector mechanisms that are
available to different classes of cells, the degree of amplification
that they can achieve through clonal expansion, the signals
that they will respond to, and the limits that will be set
on their abilities to alter function in different environmental
conditions. As all these cell types are ultimately derived from
common hematopoietic precursors, they each become distinct
from other cell types at developmental choice points that
define a time course of branching lineage relationships. This
volume showcases striking new advances that illuminate the
mechanisms governing several particularly interesting choice
points where divergent immune cell identities are established
