As the mRNA sequences of the TIRs of the oprD and opdP genes in the clinical isolate PA14 showed only minor differences to PAO1 (Winsor et al., 2016), the same experiments were performed with the clinical isolate PA14 and the corresponding PA14Δhfq mutant harboring plasmids pME1615PtacoprD::lacZ and pME1615PtacopdP::lacZ, respectively, after growth in synthetic cystic fibrosis medium (SCFM) containing 100 μM FeSO4 (Palmer et al., 2007; Tata et al., 2016). This evidence concerns the gene OPRD1 and cystic fibrosis.