The high fat-fed PyMT mice showed a stimulated primary tumor growth rate and enhanced metastasis to the lungs, effects that were associated with hepatic steatosis, pronounced macrophage infiltration and crown-like structure formation, neovascularization in the peritumoral adipose tissue, and elevated plasma MCP-1 concentrations and adipose tissue MCP-1 expression [115]. This evidence concerns the gene CCL2 and fatty liver disease.