Down‐regulation of expression has been documented in blood pDCs following ex vivo viral and CpG‐ODNstimulation,24, 39 and there was a trend towards reduction in the expression on airway pDCs during the course of the infection in patients with asthma in this study (Figure 6D), we can speculate this may suggest a shared mechanism of counter regulation between FcεRIα and IFN production in both DC populations. This evidence concerns the gene FCER1A and infection.