NKT cells expressing both invariant TCRs and NK cell receptors are an important regulatory cell subset active during initiation of innate immune responses. They are involved in a wide variety of immune responses, but the molecular details of their regulatory action are unknown. Transcriptional profiling has been used for analysis of NKT cell activation profiles, revealing that NKT cells differ from conventional T cells and would be expected to regulate immune responses by controlling dendritic cell activation.