TLR2 and rosacea: It is possible that the polymorphism at the adjacent TACR3 may be somehow involved in increasing expression of TLR2 in rosacea and therefore in upregulation of KLK5 in a calcium-dependent manner; possibly PP rosacea patients overreact, resulting in the histogenesis of rosacea papules and pustules, even though bacterial diversity and quantities are similar in rosacea lesions and in normal skin [34].