CFTR and cystic fibrosis: Interestingly, in CF cells the increased content of Cer seems to be due to the increased activity of the PM associated β‐glucocerebrosidase and nonlysosomal β‐glucosylceramidase, both enzymes involved in the catabolism of the GlcCer at the PM (1.4‐ and 1.5‐fold, respectively), compared with WT‐CFTR cells.