CVID patients with PCP IgA and IgM concentrations above 150 and 20 U/mL, respectively, have been shown to have a lower risk of developing pneumonia and bronchiectasis than those with either a PCP IgM concentration < 20 U/mL only or those with both concentrations below both the above cut‐offs.22 This evidence concerns the gene CD40LG and susceptibility to pneumonia measurement.