SLPI and cystic fibrosis: In female CF patients, increased levels of estradiol mediates upregulation of secretory leukocyte protease inhibitor (SLPI) expression via ERβ, thereby inhibiting TLR-dependent IL-8 release in cystic fibrosis bronchial epithelial cells, making female with cystic fibrosis more susceptible to infection and colonization by P. aeruginosa (4).