Primary mitochondrial diseases ('mito') are a group of genetically and phenotypically diverse disorders caused by defects in mitochondrial structure or function. Although they are individually rare, they collectively have an incidence of around 1 : 4300. Mitochondrial diseases can arise from mutations in either mitochondrial or nuclear genes, complicating genetic diagnosis. The Lily Foundation was founded by Liz Curtis in the UK in 2007 in order to raise awareness of mitochondrial diseases and to fund research into diagnosis and treatment. In this first of a new series on patient advocacy, FEBS Letters interviews Founder and CEO Liz Curtis MBE, Head of Patient Programmes Katie Waller and Research Manager Dr. Maria O'Hanlon on the aims, achievements and activities of the Lily Foundation.