This study investigated the mechanistic role of Ido1 in cancer cachexia and evaluated the therapeutic potential of its inhibition.<h4>Methods</h4>We established Lewis lung carcinoma (LLC) models in C57BL/6 mice using wild-type, Ido1-overexpressing (Ido1-OE) and Ido1-knockout (Ido1-KO) cells. Here, IDO1 is linked to cancer.