It has been found that stimulated humanized murine ε4 astrocytes secrete more CCL3 than ε3 astrocytes, and the level of CCL3 in brains of AD patients homozygous for APOE ε4 is significantly higher as compared to age-matched homozygous APOE ε3 AD individuals (Cudaback et al. 2015). Here, APOE is linked to Alzheimer disease.