BBOX1 (gamma-butyrobetaine hydroxylase 1) is a cytosolic dioxygenase that catalyzes the final step of L-carnitine biosynthesis from gamma-butyrobetaine 1. The enzyme is predominantly expressed in kidney, liver, and brain tissue, with tissue-specific transcription patterns regulated by multiple promoters and alternative polyadenylation mechanisms 1. BBOX1 functions as a metabolic checkpoint with context-dependent roles in cancer biology. In hepatocellular carcinoma, CRIP1 suppresses BBOX1 through ubiquitin-proteasomal degradation, reducing carnitine availability and promoting cancer stemness via altered β-catenin signaling 2. Conversely, in clear cell renal cell carcinoma, BBOX1 acts as a tumor suppressor by restraining TBK1-mTORC1 oncogenic signaling through disruption of TBK1-DCLK2 interaction 3. In metastatic cancer, BBOX1-produced carnitine suppresses NK cell cytotoxicity by inhibiting RhoA and preventing immunological synapse formation, enabling immune evasion 4. Beyond cancer, BBOX1 expression is upregulated in psoriasis through the α-KG-H3K9me3 regulatory axis, promoting carnitine metabolism and oxidative phosphorylation 5. Clinically, BBOX1-AS1 (an antisense lncRNA) is upregulated in multiple cancers and recurrent pregnancy loss, associated with poor prognosis and lymph node metastasis 67.