Valerie Beral was an epidemiologist who studied the role of hormonal, reproductive and infectious agents in cancer. Her work helped to identify a number of causes of cancer, along with indicating the existence of the viral causes behind cervical cancer and Kaposi's sarcoma.
Valerie was the principal investigator behind the Million Women Study, which examined how various lifestyle and reproductive factors affect women's health, with a particular focus on the impact of hormone replacement therapy on the risk of developing breast cancer.