Researchers have found that a common gene variant - carried by 1 in 3 people - may increase risk of colorectal cancer in individuals who eat processed meat.
To recognize each other, the egg and sperm carry proteins on their surfaces. The sperm one was discovered by Japanese researchers. Now, UK researchers have identified the egg one.
Numerous studies have suggested that using social media sites such as Facebook and Twitter can affect mental health and well-being. We look at the evidence.