ABCA1 and Tangier disease: Data from ABCA1 deficient mice (Hirsch-Reinshagen et al., 2004; Wahrle et al., 2004) and Tangier disease patients with non-functional ABCA1 demonstrated that in the absence of cholesterol efflux plasma APOA-I is virtually missing and APOE in plasma and brain is significantly reduced [reviewed in Oram and Vaughan (2000) and Koldamova et al. (2014)].