Invariant natural killer T cells (iNKT cells) have immune stimulatory or inhibitory effects on the immune response that are context-dependent, which is due in part to the existence of functional iNKT cell subsets dedicated to producing certain cytokines.  We have previously conducted a characterization of iNKT subsets in the thymus, including NKT1, NKT2 and NKT17 cells, through fluorescent cell sorting and RNAseq.  The data gleaned from this study demonstrated that iNKT subsets were highly divergent from each other, and allowed us to identify a number of novel markers for these subsets.  These data led us to consider how the transcriptional signatures of iNKT subsets in peripheral organs compare to those in the thymus.  This question is particularly relevant given that the final maturation of at least some of the peripheral subsets takes place after egress from the thymus.  We have now initiated transcriptomic analyses of iNKT subsets in peripheral organs, employing a recently developed variation of RNAseq in which relatively small numbers of cells (typically 400) are collected by fluorescence sorting and then reverse transcription of RNA is performed directly on cell lysates, followed by PCR amplification and sequencing.  We will present data from studies of several peripheral iNKT subsets obtained from the spleen, liver and lung.  We will also describe modifications to our sorting protocol that allow us to distinguish NKT2 cells from a separate iNKT population that expresses a mix of NKT1 and NKT2 markers.