Of relevance to the RA inflammatory lesion, stimulation of blood pDC precursors with signals including CD154, influenza virus, or CpG oligonucleotides induces production of large amounts of cytokines, including IFN-α, IFN-β, and TNF-α; induction of DC differentiation; and stimulation of APC function [3,39,44,59]. This evidence concerns the gene CD40LG and rheumatoid arthritis.