The aim of our study was to investigate the frequency of factor V Leiden (G1691A), factor II Prothrombin (G2021A), MTHFR C677T, MTHFR A1298, and combined polymorphisms in a Greek population by using real-time polymerase chain reaction methods and their possible association with family history of cancer and cardiovascular diseases (CVDs), as well as environmental epigenetic factors that might influence genotype expression. This evidence concerns the gene F2 and cancer.