SNCA and Gliosis: Additionally, in mice models expressing different human variants of APOE (A53T/E2, E3, E4), they noted the greatest formation of toxic α-synuclein agglomerates associated with gliosis in A53T/E4 mice, whereas ε2 variants exhibited protective function reducing α-synuclein pathologies and increasing the survival of mice, as well as improving their motor performance.