This review systematically summarizes the multifaceted mechanisms by which DDIT4 participates in tumor immunomodulation, primarily through its inhibition of the PI3K-Akt/mTOR pathway to induce autophagy activation and metabolic reprogramming; furthermore, it comprehensively examines DDIT4’s regulatory effects on various components within the tumor immune microenvironment, including tumor cells, both innate and adaptive immune cells, and immunomodulatory cytokines. The gene discussed is AKT1; the disease is neoplasm.