Previous work had evidenced the transcriptional activation of mucin by Pseudomonas aeruginosa lipopolysaccharide in cystic fibrosis [46] and PMP [47], suggesting higher bacterial densities, particularly of species such as P. aeruginosa, may be contributing to increased MUC2 expression and therefore volume of peritoneal mucin. The gene discussed is MUC5AC; the disease is cystic fibrosis.