IDO1 and retinal disorder: Compared with wild-type mice, mice with a genetic ablation of Ido1 had a significantly reduced density of pulmonary blood vessels.111 Furthermore, neovascularisation in mouse models of oxygen-induced retinopathy and lung metastasis was significantly reduced in mice lacking Ido1. 112 In line with the cell motility-promoting effects of Trp catabolites mediated via AHR activation (see above), the expression of Trp-catabolic enzymes has been shown to affect metastasis formation.