When the low-density lipoprotein receptor (LDLR) is missing, saturated or inhibited, chylomicron remnants (CRs) containing all-trans-retinyl esters (atREs) can be cleared from circulation by interaction with cell-surface heparan sulfate proteoglycan (HSPG) and secreted apolipoprotein E (apoE). This complex is then presented to LDL receptor-related proteins (LRPs; reviews May et al. 2007, Li et al. 2001, Hussain 2001) for internalization (Ji et al. 1993).