IL17A and melanoma: Animal studies have shown that N1 anti-tumor neutrophils in the pre-metastatic niche prevented breast cancer metastasis to the lung40,51, while N2 immunosuppressive neutrophils in the pre-metastatic niche promoted liver cancer metastasis from the spleen52, breast cancer metastasis (in conjunction with IL-17 producing gamma delta T cells) to the lymph nodes and lung53, and melanoma metastasis to the lung in nude mice injected via tail vein with neutrophils and melanoma cells54.