Did you know that some people are resistant to HIV? People who carry two copies of the CCR5 delta-32 mutation are resistant to *most* strains of HIV. (Still not something to test out!) Check your genes to see if you carry this mutation.
Twins tend to ‘run in families’, which is a colloquial way of saying that there is a hereditary component that increases the likelihood of having twins. Check your genetic data (women only :-) to see if you are more likely to have twins.
To have red hair, you need to carry two variants in the MC1R gene. We all know our hair color, but it turns out that if you carry one MC1R genetic variant (and don’t have red hair) you are still at an increased risk for skin cancer.