GCSAML and urticaria: For C1ORF150, the goals of this review are as follows: (a) summarize C1ORF150’s primary structural features, including informative comparisons to HGAL; (b) define what has been observed to date regarding C1ORF150’s regulated expression (19, 21) and phospho-modifications in myelo-erythroid progenitors (22) and mast cells (24); and (c) highlight apparent roles of C1ORF150 during mast cell activation as implicated via GWAS associations of a C1ORF150 splice variant with urticaria (23, 25, 26).