ILC2 is differentiated from ILC3 in response to activation of TLR2 and produces IL-5 and IL-13 (Alderton 2012; Wills-Karp 2004), which plays vital role in initiating and promoting immune response among asthma patients, and leads to the accumulation of eosinophils in BALF (Izuhara 2017; Lloyd and Hessel 2010). This evidence concerns the gene TLR2 and asthma.