It has been shown that increasing the concentration of divalent cations (Zn2+, Ca2+ and Mg2+) can increase the antimicrobial activity of AMPs such as kappacin and DCD-1L (see Section 6.1); however, there are conflicting reports as to the whether these cations are present in significantly higher concentrations in CF patients.84–87. This evidence concerns the gene ADSL and cystic fibrosis.