Professor Hilde Nilsen is an internationally recognized expert in DNA repair who is driven to comprehend how spontaneous DNA damage and its repair affect human health. Her research has helped to demonstrate how base excision repair (BER) affects mutation accumulation and B-cell maturation. She outlined mechanisms causing neurodegeneration in several rare diseases caused by DNA repair defects. Her focus now is understanding common neurodegenerative diseases. Her group has demonstrated that, in a C. elegans Parkinson's disease (PD) model, normal aging is accompanied by uncoordinated BER, a failure that leads to breaks in the mitochondrial and genomic DNA. An important insight has been that DNA repair deficiencies, whether induced by mutation or aging, are compensated by BER-dependent reprogramming of gene activation and mitochondrial stress responses. The current goal is to model BER-mediated transcription in human models to define whether this is a missing piece in the puzzle of PD.