AGXT2 and cystic fibrosis: P. aeruginosa has been shown to upregulate the olsBA operon, plcP, agt1, and agt2 upon interaction with human epithelial cells (Frisk et al., 2004; Chugani and Greenberg, 2007), and in sputum samples from CF patients P. aeruginosa upregulates olsBA and agt2 (Rossi et al., 2018).