At Sanger, I was supported by a EMBO long-term fellowship to work with Dr Logan and together we tackled a puzzle in epigenetics: why parentally biased control of gene expression is maintained in the mammalian brain. By mapping a high-resolution allelic imbalance landscape in the mouse olfaction system, I identified and validated a candidate gene Trappc9 that shows a strong maternal expression bias exclusively in the brain, and followed it up by phenotypical characterization of the knockout mice lacking this key gene.