There are plenty of candidate mechanisms for the well-known longevity gap between men and women. Here is another - the potency of your immune system: "women have a more powerful immune system than men. In fact, the production of estrogen by females could have a beneficial effect on the innate inflammatory response against bacterial pathogens. ... More specifically, estrogen naturally produced in women seems to block the production of an enzyme called Caspase-12, which itself blocks the inflammatory process. ... The positive effect of natural estrogen on our resistence to infection is also exhibited with synthetic hormones such as 17-beta-estradiol. This finding might therefore open the door to new therapeutic applications that reinforce the immune system." A more robust immune system can go a long way to boosting life expectancy. In addition to dealing with pathogens, the immune system is also responsible for eliminating damaging senescent cells and cancer cells, for example.