HA polymer HA polymer Growing HA is extruded from the cell by ABCC5 As hyaluronan (HA) is synthesised, it is continually extruded from the cell by the ABC transporter C5 (ABCC5), also called multidrug resistance-associated protein 5 (MRP5) (Schulz et al. 2007). Authored: Jassal, B, 2012-02-24 Edited: Jassal, B, 2012-02-24 Pubmed17540771 Reactome Database ID Release 432142859 Reactome, http://www.reactome.org ReactomeREACT_121051 Reviewed: D'Eustachio, P, 2012-03-28