Statistical Analysis
For data analysis, a MS-Excel sheet was downloaded from the manufacturer’s website (https://www.qiagen.com) NormFinder (https://moma.dk/normfinder-software) was used to select the best housekeeping genes for normalization. ACTB and HPRT1 were found as the most stable combination of housekeeping genes in the patients and non-CF control subjects. Gene expression results were calculated using the 2-ΔΔCT method. Unpaired student t-test was performed to compare differentially expressed genes between mild/severe siblings and patients/healthy controls (p≤0.05, 2-fold change (FC)). The pathway enrichment analysis was performed using WebGestalt tool. (http://www.webgestalt.org/).