I think it might be values.
His mother could encourage him to wear sunblock and sunglasses.
The answer is:
Age
This is because if your young your organs are not as developed. When your older your body handles more because it is developed fully.
Answer:
No
Explanation:
She is incorrect in saying that she will not get breast cancer with 100% certainty. Although, since her BRCA1 and BRCA2 alleles were found to have no mutations signalling breast cancer, this means that there might be a very small chance that she could still develop breast cancer.
Even though it is highly unlikely that she will develop breast cancer, there is still a very small chance that it can occur.