SLC25A33 encodes a mitochondrial pyrimidine nucleotide transporter that plays essential roles in mitochondrial genome maintenance and cellular metabolism 1. The protein selectively transports uridine, thymidine, guanosine, cytosine, and inosine nucleoside di- and triphosphates across the inner mitochondrial membrane via an antiport mechanism, importing nucleoside triphosphates in exchange for diphosphates to support mitochondrial DNA and RNA synthesis 1. SLC25A33 is critical for mitochondrial biogenesis and function, particularly in response to IGF-1 signaling, where it regulates cell growth and proliferation by controlling mitochondrial DNA replication and transcription 2. Recent studies demonstrate that SLC25A33 contributes to inflammatory responses in M1 macrophages by facilitating mitochondrial DNA synthesis and release, which promotes mitochondrial ROS production and VDAC oligomerization, ultimately activating the cGAS-STING inflammatory pathway 3. The transporter is also involved in metabolic reprogramming, as its deficiency affects methionine metabolism and promotes fibrosis through the mTOR pathway 4. Additionally, SLC25A33 enhances dendritic cell endocytosis and may associate with mitochondrial oxidative phosphorylation 5. The gene shows widespread expression across tissues, particularly in the central nervous system, and is enriched in luminal tumor cells in prostate cancer 67.