CKD273 is a capillary electrophoresis–MS-based, multidimensional urinary biomarker, consisting of 273 defined urinary peptides (mainly collagen, albumin, alpha-1-antitrypsin, fibrinogen, ..., fragments), identified by Good et al. [34] in 2010 in the context of CKD, irrespective of the underlying pathology. The gene discussed is SERPINA1; the disease is chronic kidney disease.