BRCA1 and cancer: It is already known that even at such a high risk of cancer as e.g. 80% risk of developing breast/ovarian cancer in carriers of the BRCA1 mutation also constitute a significant share among carcinogenic factors environmental factors that may have the character of chemical factors (carcinogens contained in tobacco smoke, alcohol, arsenic concentration), physical (ionizing radiation, UV), biological (oncogenic HPV, EBV viruses) also constitute a significant share among carcinogenic factors [22].