Blood type can really affect a person’s health status, the researchers at Harvard University found out.

The most “dangerous” group, in their opinion, is AB (IV) Rh negative. There are few people with such a blood type on Earth - only 8% of the world's population. And if they need blood, finding someone to donate it is not easy.

According to scientists, people with this blood type have a few chanced to have children. It is an extremely rare case when children of different sexes are born to people having AB type. Meanwhile, women with this blood type are more likely to have cancer.