Because of the direct effect of PQS on expression of HIF-1α (Legendre et al., 2012), it would be of interest to perform further studies under microaerobic conditions, such as those found in the CF lung (Schobert and Jahn, 2010), when PQS can still be synthesized and exert its influence on host adaptation to low oxygen through HIF-1α. Here, HIF1A is linked to cystic fibrosis.