Furthermore, in response to physical stimuli, for example, in inducible urticaria, non-IgE-mediated mechanisms are known to be triggered, involving adhesion G protein-coupled receptor E2 (ADGRE2 or EMR2) and ion channel TRPV2 for mechanical, thermal, and osmotic stimuli; NOX2 in response to UVA irradiation; suppression of tumorigenicity 2 (ST2) and P2X1 receptors for alarmins. Here, IGHE is linked to urticaria.