Thus, ApoE knockout (KO) rodent models have been favored in atherosclerosis studies and have provided valuable insights into mechanisms underlying this disease (Chistiakov et al., 2017; Iqbal et al., 2016; Niimi et al., 2016; Piedrahita et al., 1992; Plump et al., 1992). The gene discussed is APOE; the disease is atherosclerosis.