Growth factors (GFs) are produced by varies tissues. They are acting as autocrine and paracrine factors. These factors stimulate the division of the cells and have trophic properties. Abnormal expression of the activities of these substances can result in profound dysregulation of the growth and apoptosis and they cause the development of neoplasia. GFs are acting upon specific receptors existing in cell membranes. The production of GFs is growing in cells that are being transformed. On the contrary to the normal the neoplasmatic cells are showing lesser dependence from exogenous GFs. That is partly connected with the ability of these cells to produce own GFs.
The activity of the most important GFs (epidermal growth factor, transforming growth factor ß, insulin-like growth factors I and II, fibroblastic growth factor – 2) in the organism has been discussed. In the presented article spatial attention was shown the stimulating influence of these factors on the normal and neoplasmatic cells of the breast gland.