APOE and carotid atherosclerosis: Cath1 on chromosome 12, Cath2 on chromosome 5, Cath3 on chromosome 13, and Cath4 on chromosome 6 are four significant QTL for carotid atherosclerosis thus far mapped in two Apoe−/− mouse intercrosses (Li et al. 2008; Rowlan et al. 2013a).