Many studies showed that the low AA status depends on the accelerated metabolism of this FA, that increased expression and activity of Δ5- and Δ6-desaturases is associated with severe mutations in the CFTR gene and also that this was more frequent in patients with pancreatic insufficiency and worse pulmonary function [12,13,14,23,31,32]. The gene discussed is CFTR; the disease is exocrine pancreatic insufficiency.