The mammary gland is an organ comprised of branched ductal network terminated by secretory alveoli and embedded in mesenchymal stroma. Mammary alveoli, built by myoepithelial and epithelial cells with apico basal polarity, obtain their functional differentiation only during lactogenesis. For this reason they represent a good model for studies on differentiation process of epithelium.

The dentin formation and mineralization proceeds in the defined, matrix-mediated manner. It begins from the secretion of the organic matrix and ends with the complete mineral deposition. The dentin apposition takes place when odontoblasts begin the secretion of type I collagen into the extracel- lular compartment. Type I collagen is the main component of the dentin extracellular organic matrix and forms the specific scaffold for the deposition of dentin hydroxyapatite crystals.

Dental enamel is the most mineralized tissue all over the body. The enamel development begins with the organic matrix secretion. The enamel extracellular matrix mainly consists of amelogenins and enamelins. As the enamel maturation progress the organic matrix undergoes proteolitic degradation. The remnants, which remain after the degradation are subsequently withdrawn and replaced with hydro- xyapatites crystals which form the enamel prisms. The enamel secretion and maturation can be modified by fluoride ions supplemented per os.

The function of mast cells in angioneogenesis is not completely known. Their role in the processes of the stimulation, inhibition and regulation of the angiogenesis is connected with mediators of angiogenesis produced by mast cells, e.g. heparin, histamin, bFGF, VEGF, chymase, tryptase and hydrolases. The enzymatical actions of mast cells on extracellular matrix, mostly by proteases, change its structure and facilitate creation of three-dimensional vascular system.

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.