Fig. 1.

Innate lymphocyte lineages. All innate lymphocyte lineages can be generated from the common lymphoid progenitor (CLP) ([137], and A.M., A.D., unpublished data). Based on the finding that Id2 ^−/− and Tox ^−/− mice lack all innate lymphocyte lineages, a putative Id2 and/or Tox-dependent common ILC precursor (CILP, ILCP) has been proposed [28, 29]. After specification into the various lymphocyte lineages controlled by the expression of lineage-defining transcription factors and cytokines, various effector fates can be assumed