IL6 and urticaria: Genetic studies have begun to explore association with urticaria and polymorphisms in histamine‐related genes (e.g., FcεRI, HNMT), leukotriene‐related genes (e.g., ALOX5, LTC4S), the prostaglandin E2 receptor gene (PTGER4), and single nucleotide polymorphisms (SNPs) in pro‐inflammatory cytokine genes (e.g., IL‐6, TNF‐α).8, 9, 10