PARP6 is a mono-ADP-ribosyltransferase that catalyzes mono-ADP-ribosylation (MARylation) of target proteins, functioning as a post-translational modifier with diverse cellular roles 1. In neurons, PARP6 regulates hippocampal dendrite morphogenesis, a process critical for neural circuit formation, with its catalytic activity essential for proper dendritic complexity 2. PARP6 catalytic activity is required for postnatal survival in mice, and loss-of-function mutations in humans cause neurodevelopmental disorders including microencephaly, intellectual disability, and epilepsy 3. PARP6 functions as a negative regulator of cell proliferation through cell cycle control via direct ADP-ribosylation of checkpoint kinase 1 (Chk1), maintaining centrosome integrity and mitotic spindle formation 45. In cancer contexts, PARP6 shows differential roles: its knockdown promotes apoptosis and inhibits invasion in colorectal adenocarcinoma 6, while PARP6 positivity correlates with better prognosis and lower proliferation rates 5. PARP6 has been identified as a biomarker in B-cell acute lymphoblastic leukemia, with implications for disease relapse 7. PARP6 associates with microtubule-binding proteins and localizes to various cellular compartments including endoplasmic reticulum and nuclear envelope 3.