Participants 100% agreed on the need to establish recommendations/guidelines for the management of immunodeficiencies in hematological malignancies (CLL, MM, lymphoma, HSCT); these would include an immunological evaluation in the initial patient’s assessment with a detailed medical history, a physical examination and total proteins and protein electrophoresis in patients with B-cell neoplasms, as well as the quantification of IgG, IgA and IgM levels and IgG subclasses when SID is suspected. The gene discussed is CD40LG; the disease is B-cell chronic lymphocytic leukemia.