Friends may be an important influence for young women's risk of HIV infection as they serve as a medium to discuss norms about gender and sexuality and are a social network through which young women form sexual partnerships. In 2011, young women participating in a Conditional Cash Transfer (CCT) trial in South Africa were asked about their friendships in detail. Results showed that friends' characteristics were linked to: a young woman's likelihood of being HIV positive or having Herpes Simplex 2 virus; the age of her sexual partners; and the likelihood of her being sexually active.