Six of our urticaria-associated variants are pointing to genes that are directly implicated in type 2 immune response and/or mast cell physiology (CBLB, FCER1A, GCSAML, STAT6, TPSD1, ZFPM1)33–35, one in the complement innate immunity (C4A), and one involved in NF-κB signaling, a transcription factor known to contribute to the pathogenesis of various inflammatory diseases when deregulated36. The gene discussed is C4A; the disease is urticaria.