TP53 and ovarian cancer: Therefore, it is also possible that characteristics of the specific physiological environment in the ovarian tissue, such as the existence of extracellular survival factors (e.g., extracellular catecholamine hormones) and/or BRCA1-defective ovarian cancer cells expressing higher levels of anti-apoptosis factors (e.g., ADRB1) overwhelm the p53-activated apoptosis.