In aging population growing up rapidly causes of cancers are observed. Lost of immunological answer caused by DNA double-strand breakes, longer exposition to carcinogens, decreasing activity of DNA-repair system in aging cells, defects of supressor genes are caused carcinogenesis. DNA-defects of aging and cancer cells by hipermethylation GpC island of gene promoters are observed. Changes in extracellular matrix of aging and transformed cells are responsible forcell migration causing metastasis.

Homocysteine, a sulphur-containing non-structural protein aminoacid is a non-lipid factor in the pathogenesis of artheriosclerosis. The metabolism of homocysteine and the processes responsible for the high serum level of this aminoacid are described. The pathogenesis of artheriosclerosis depends directly or indirectly on high serum levels of homocysteine, which generate disorders in proteins, DNA and lipid methylation, changes the expresion of some genes and secretion of EDRF.