The Apoetm1Unc mutant strain was developed in the laboratory of Dr. Nobuyo Maeda at The University of North Carolina at Chapel Hill. The 129-derived E14Tg2a ES cell line was used. The plasmid used is designated as pNMC109 and the founder line is T-89 in the primary reference. The C57BL/6J strain was produced by backcrossing the Apoetm1Unc mutation 10 times to C57BL/6J mice. Previously mice backcrossed 6 times (N6) to C57BL/6J mice were distributed solely. Mice from the N6 generation are homozygous for pink-eyed dilution p giving them pink eyes and a silver coat color. The E14Tg2a ES cell line carries this recessive mutation which remains linked to the targeted Apoe gene on Chromosome 7 at this backcross generation. Mice from the N6 colony are no longer available for distribution.