The European Respiratory Society (ERS) published guidelines for bronchiectasis management in 2017 which recommends a minimum bundle of investigations that includes complete blood count (CBC), Immunoglobulin A (IgA), Immunoglobulin M (IgM) and immunoglobulin G (IgG) in all bronchiectasis patients [1] with further investigations to be done on the clinical suspicion and on the treating physician’s discretion. The gene discussed is CD40LG; the disease is bronchiectasis.