Petr Ježek, Dr., PhD., DSc., has served since 1990 as Head of the Department of Mitochondrial Physiology No.75, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic, studying mitochondria from bioenergetics up to their ultrastructure since 1981. Studies of mitochondrial uncoupling proteins were his major interest in the past, as well as mitochondrial transport, hypoxia and cancer-specific metabolism. He also studied mitochondrial morphology changes using 3D super-resolution fluorescence and FIB/SEM microscopy of cristae morphology changes and mitochondrial nucleoids. Recently he has been focusing on insulin secretion mechanisms and its relation to homeostasis of reactive oxygen species, studying pancreatic beta cells, their mitochondria, and redox signaling