APOC1 and Alzheimer disease: Furthermore, we analyzed the correlation between polymorphisms of three loci within APOE gene cluster, i.e. two located in proximity of TOMM40: a polyT length polymorphism in intron 6 (‘523) and SNP in intron 2 (‘650), as well as SNP adjacent to APOC1 gene: rs4420638 (‘638), and concentration of measured biochemical parameters in AD patients, related and unrelated controls in Polish population.