CFTR and cystic fibrosis: In the present study, glucose metabolism before and after treatment with CFTR modulators was investigated through the simultaneous measurement of the direct determinants of glucose regulation, i.e., beta-cell function, insulin clearance and insulin sensitivity, and the evaluation of their dynamic interplay in two cohorts of children and young adults with CF treated with Lumacaftor/Ivacaftor and Elexacaftor-Ivacaftor-Tezacaftor, respectively.