CD40LG and agammaglobulinemia: As emphasized in “International Consensus Document (ICON): Common Variable Immunodeficiency Disorders” published by a committee of immunology experts, patients should be diagnosed according to revised CVID criteria, taking into consideration the following aspects: (i) hypogammaglobulinemia must be accompanied by low levels of IgA or IgM; (ii) CVID patients should have an impaired response to either T-dependent or T-independent stimuli; (iii) differential diagnosis of hypogammaglobulinemia to exclude other diseases should be performed (Bonilla et al., 2016).