VIM and cystic fibrosis: Significant correlations were, however, seen between intra-islet collagen density and the putative α-cell EMT phenotype in the age-matched donors to the CF cohort (donor age <31 years: intra-islet collagen vs vimentin-positive α-cells; r = 0.972; P = 0.006; Fig. 3E, F and G).