CFTR and infection: Lentiviral infection of Caco-2/15 cells, with the same vector carrying a scrambled sequence, neither affected CFTR mRNA (100 ± 24.9 vs. 98 ± 13.7 %, n = 4–16) nor protein expression (100 ± 11.5 vs. 99 ± 11.5 %, n = 4) compared to non-infected cells (data not shown).