In order to gain insights into the effect of omega-3 and omega-6 in the growth of a sub-tumorigenic dose of melanoma cells dependent on an acute inflammatory response, in this study, mice were treated by gavage with omega-3-rich fish oil or omega-6-rich soybean oil, or a mixture of these oils in a ratio of 1:1, and the tumor growth, as well as the concentrations of inflammatory mediators (LTB4, LTB5, prostaglandin E2 (PGE2), and prostaglandin E3 (PGE3)) and cytokines (IL-6, IL-10, and CXCL1) in the tumor microenvironment, were evaluated. This evidence concerns the gene IL6 and neoplasm.