In anti-tumor immunity, GM-CSF treatment increases the frequency of tumor-specific Th1 T cells [45], and, in experimental autoimmune thyroiditis, GM-CSF treatment has been shown to both enhance IL-6–dependent Th17 cell responses and increase the number of immunoregulatory CD4+CD25+ T cells [46, 47]. Here, CSF2 is linked to autoimmune thyroid disease.