The Role of Interleukin-9 in Cancer.

Interluekin-9 (IL-9) is produced predominantly by helper T cells such as Th2 and Th9 cells. It normally functions through the activation of a JAK/STAT pathway and plays a critical role in immunity and the pathogenesis of cancer. In cancer, it yields different responses depending on the cancer cell line involved. This review is a summary of what is known about the involvement of IL-9 in various cancer cell lines as well as its role in immunity with a focus on allergic responses.