NUDT13 is a mitochondrial NAD(P)H pyrophosphatase that hydrolyzes reduced pyridine nucleotides NADH and NADPH into their respective products (NMNH and AMP/2',5'-ADP), with marked substrate selectivity for reduced over oxidized forms 1. The enzyme localizes exclusively to mitochondria via an N-terminal targeting peptide, suggesting a role in regulating mitochondrial NAD(P)+/NAD(P)H ratios and redox homeostasis 1. In colorectal cancer, NUDT13 functions as a tumor suppressor by stabilizing the PKM1 protein through reduction of its poly-ADP ribosylation at key residues within the Nudix box motif, thereby promoting an oxidative phosphorylation metabolic phenotype that inhibits CRC initiation 2. This stabilization mechanism is catalyzed by PARP1 at specific PKM1 sites, and PARP1 inhibition can partially rescue the tumor-suppressive effects of NUDT13 loss 2. Genetically, NUDT13 expression variants are associated with uterine fibroid risk across multiple tissues including subcutaneous adipose tissue 3, and NUDT13 methylation status correlates with colorectal cancer patient survival, particularly in aggressive disease phenotypes 4. Additionally, NUDT13 expression levels positively correlate with MFSD4, a putative gastric cancer metastasis suppressor 5, suggesting broader tumor-suppressive functions across cancer types.