This is the cells we will talk about,
the NK cells seen in blood smear.
As you can see, they are large
granular lymphocytes with granules
that are responsible for killing
of tumor cells or virus infected cells.
NK cells originate from
hematopoietic stem cells
and belong to a
growing family that
we call Innate Lymphoid Cells,
ILC, which all derive
from an Id2 positive resource.
And depending on the cytokine
milieu and on the transcription
factors that are being activated,
these resource can give
rise to different group of ILC.
NK cells, as you can see in these
figures, belong to group one.
ILC is those cells which release
interferon gamma and have also,
at least in the case of
NK cells, the ability
to kill viral infected cells.