FHOD1 (Formin homology 2 domain-containing protein 1) is a member of the Diaphanous-related formins (DRFs), a family of proteins characterized by the presence of a GTP-binding domain (GBD), formin homology (FH) 1 and FH2 domains, a coiled-coil motif, and a diaphanous autoregulatory domain (DAD). Accumulating evidence indicates that FHOD1 not only modulates intracellular signaling pathways in tumor cells but also influences multiple components of the tumor microenvironment (TME), including T cells, B cells, cancer-associated fibroblasts (CAFs), and various cytokines. Dysregulated expression and functional impairment of FHOD1 have been implicated in the development of tumor immunosuppression. Specifically, FHOD1 interferes with the function of chemokine receptors responsible for guiding immune cell trafficking to tumor sites, thereby compromising the efficient infiltration of immune cells into the TME. This deficiency limits the capacity of immune cells to target and eliminate tumor cells. Furthermore, FHOD1 aberrantly activates intracellular signaling pathways within immune cells, impairing their ability to recognize and respond to tumor cells effectively. Consequently, FHOD1 contributes to an immunosuppressive TME, creating a permissive environment for tumor progression and metastasis (PMID: 40364836).