A brief history of the human liver peroxisome

The human liver peroxisome deserves a special review because it differs from peroxisomes in laboratory animals and cultured cells. We provide an overview of the historical stepping stones, with special emphasis on electron microscopy, enzyme- and immunocytochemistry, and morphometry. The contributions from several hundreds of patients, children with inherited diseases and adults with acquired illnesses are summarized. Intriguing findings such as liver peroxisomes of a patient changing over time, or the patient series with peroxisome mosaics in the liver, are highlighted. We compare our own data with the more recent discoveries, in particular the endoplasmic reticulum-peroxisome membrane contact sites and their inherited deficiencies: retinal dystrophy with leukodystrophy (RDLD). For complete diagnosis, expanded phenotyping and understanding the diseases, we urge the examination of human liver tissue.