When compared with the control group by using chi-square test to estimate the risk of each of the ApoE alleles and the genotypes in the tumor and CVD groups, the frequency of ε3 and E3/E3 was significantly decreased in the tumor patients with or without CVD group (P < 0.01), while those of the ε4 and E3/E4 were significantly increased (P < 0.001), suggesting a a risk factor ε4 in tumor and CVD genesis. This evidence concerns the gene APOE and neoplasm.