IL17A and rosacea: Recent molecular studies have identified critical signaling pathways in rosacea, highlighting the roles of toll-like receptor (TLR)2, LL37 production (8), the interleukin (IL)-17 signaling pathway (9), and the LL37- mammalian target of rapamycin (mTOR) and Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathways (10, 11).