Scientists have discovered a way to reactivate the thymus to create new T-cells in adults with HIV. The new therapy can be used to stimulate the production of vital immune cells, called “T- cells,” in adults with HIV infection. HIV disease destroys T-cells, leading to collapse of the immune system and severe infection. The thymus gland, which produces T-cells, gradually loses function over time (a process called “involution”) and becomes mostly inactive during adulthood. Because the thymus gland does not function well in adults, it is difficult for HIV-infected adults to make new T-cells. Thus, therapies that stimulate the thymus to produce new T-cells could help HIV-infected patients to rebuild their embattled immune systems.