Stimulation of keratinocyte toll-like receptors (TLR) 2-6 by pathogens (e.g., Staphylococcus aureus) or scratching (in case of TLR3) and house dust mite (HDM)-induced activation of protease-activated receptor 2 (PAR2) also significantly contribute to pruritus/AD via TSLP secretion (Takai et al., 2014; Smith et al., 2019; Szöllősi et al., 2019; Buhl et al., 2020). This evidence concerns the gene F2RL1 and Alzheimer disease.