T-helper 9 cells are a subset of T-helper cells, which are crucial components of the immune system. They play a significant role in orchestrating immune responses, particularly in the context of allergic reactions and asthma. T-helper 9 cells produce specific cytokines, such as IL-9, that help regulate inflammation and promote the activity of other immune cells. These cells are characterized by their ability to enhance the production of IgE antibodies, which are often involved in allergic responses. Research into T-helper 9 cells is ongoing, as understanding their function could lead to new treatments for allergies and other immune-related conditions.