In our current study, we found that intrinsic mPGES-1 was associated with the expression of collagen-related genes, especially col3a1, col4a1, col4a2, and col8a1, and that genetic and pharmacologic depletion of mPGES-1 effectively decreased collagen deposition in the tumor microenvironment in a mouse model. The gene discussed is COL4A1; the disease is neoplasm.