TIGD5 (tigger transposable element derived 5) is a nuclear DNA-binding protein encoded at chromosome 8.3 with complex and context-dependent functions in cancer biology. In ovarian cancer, TIGD5 is frequently co-amplified with the oncogene MYC in the 8q24 region 1. Paradoxically, while high TIGD5 mRNA expression correlates with poor prognosis in ovarian cancer patients 1, experimental overexpression of TIGD5 in ovarian cancer cell lines suppressed cell growth, adhesion, and invasion in vitro and reduced tumor growth in vivo, suggesting tumor suppressor functions 1. In hepatocellular carcinoma (HCC), TIGD5 expression is significantly upregulated and correlates with worse overall survival, functioning as an independent prognostic marker 2. TIGD5-high HCC epithelial cells show enriched extracellular matrix organization, growth factor signaling, and immune regulatory pathways 2. Beyond cancer, the TIGD5 rs75547282 variant is associated with increased autism spectrum disorder (ASD) risk in Han Chinese populations, with the T allele activating TIGD5 expression 3. These findings reveal TIGD5 as a multifunctional transposable element-derived gene with distinct roles across different malignancies and neurological conditions, warranting further investigation as a potential biomarker and therapeutic target.