Biliverdin is reduced to bilirubin Bilirubin is the breakdown product of heme, causing death if allowed to accumulate in the blood. It is highly lipophilic thus requires conjugation to become more water soluble to aid excretion. EC Number: 1.3.1.24 Reactome Database ID Release 43189384 Reactome, http://www.reactome.org ReactomeREACT_22177 Reviewed: Sassa, S, 2007-01-24 10:18:36