In support of this, varying alterations in the proportions of FOXP3+ Treg [18], Th17 [19], mucosal-associated invariant T (MAIT) [20] cells and changes in the relative production of a number of cytokines in peripheral blood of people with CF have been reported, but it is unclear to what extent this is related to the underlying CFTR defect or whether it is related to infection. The gene discussed is CFTR; the disease is cystic fibrosis.