Figure 4 shows the concentration of these molecules in the sera of CVID patients before and 72 hours after IVIg therapy. Both IL-4 and CXCR4 decreased after Ig infusion in agreement with the gene array analysis [23], [24]. On the contrary IL-8 level was not significantly modified after Ig treatment as it happened for the expression of the coding gene [25]. Here, IL4 is linked to common variable immunodeficiency.