IDO1 and fibrosarcoma: For instance, the role of the kynurenine pathway in inducing changes in macrophage phenotypes was previously investigated in the murine macrophage cell line RAW 264.7 and the murine fibrosarcoma cell line MC57, showing a role for IDO in cell adhesion, metalloproteinase expression and in the expression and activity of the cyclooxygenase enzymes [64].