KLK5 and rosacea: In a study developed in 2018 (Citron Essential Oils Alleviate the Mediators Related to Rosacea Pathophysiology in Epidermal Keratinocytes), it was demonstrated that citron essential oils have a suppressive effect on LL-37, KLK5, and other pro-inflammatory mediators involved in the pathophysiology of rosacea [99].