This week, more than 7,000 girls and young women will be infected with HIV. In the hardest-hit countries, girls account for more than 80 percent of all new HIV infections among adolescents. The HIV epidemic can only be ended by advancing gender equality—and removing gender-based drivers of the disease. If we invest in girls’ schooling, health benefits will follow. A better-educated girl is less likely to get HIV and more likely to have control over her body and be able to make her own choices about when she marries and how many children she’ll have. And it not only makes a difference for her, it makes a difference for generations to come. Her children are more likely to survive infanthood, more likely to be vaccinated, and more likely to go to school themselves.