Inflammation is an important feature of the tumor microenvironment in melanoma, and previous studies showed that inducible nitric oxide synthase (INOS), one of the most common inflammation factors, is an important inducer of melanoma tumorigenesis, tumor growth, invasion and metastasis [9, 10], and INOS abrogation has been proved to contribute to melanoma treatment. Here, NOS2 is linked to melanoma.