TPSAB1 and urticaria: Taking advantage of proteomics data, we show that the GCSAML urticaria risk-allele associates with greater plasma levels of five proteins; TPSAB1, TPSB2, KIT, SIGLEC6, and SELP. TPSAB1 and TPSB2 both encode tryptases, while KIT encodes mast/stem cell factor receptor (SCFR).