The interaction between APOE4 and MLVs appears to play a role in AD [137]: APOE4 is likely linked to reduced expression of lymphatic vessel genetic markers and peripheral lymphedema-associated genes, and therefore, APOE4’s action could result in the early shrinkage and attenuated function of MLVs, diminishing CSF flow and decreasing Aβ clearance. This evidence concerns the gene APOE and Alzheimer disease.