The role of type 2 immunity in breast cancer development.

Breast cancer is the malignancy with the highest incidence and mortality in women worldwide, with no effective treatments for advanced disease. Immunotherapy has shown promising results in cancer treatment; however, improving therapeutic strategies requires a better understanding of immune regulation mechanisms within the tumor microenvironment. One cell population that has become relevant in this disease is the Th2 lymphocytes present in breast tumors, which produce IL-4 and IL-13 and can promote tumor growth and immune dysfunction. However, the Th2 response has recently been reported to have anti-tumor properties. These contradictory findings about Th2 in breast tumor development may reflect differences in the models used, which represent distinct tumor microenvironments, and the complexity and diversity observed in human patients. This article reviews the most relevant implications of Th2 cells in breast cancer development.