To characterise pDC activation and function in a primary P. falciparum blood-stage infection, we isolated highly purified pDC for gene expression analysis, monitored the expression of co-stimulatory markers CD86, CD80 and CD40 and measured pDC responsiveness to TLR7 and TLR9 stimulation at baseline and at peak-infection. The gene discussed is TLR9; the disease is infection.