a. Tissue-specific regulation of ADK isoforms in adrenal gland, brain, heart, kidney, liver, pancreas, spleen, muscle and thymus is depicted. The signs ++++, +++, ++, + and – denote, very high, high, moderate, low and no expression, respectively. b. Developmental regulation of ADK isoforms in the brain of mice from embryonic (E5 –E20), postnatal (P4–8), and adult stages. c. Localization of ADK-S in the cytoplasm of astrocytes and localization of ADK-L in the nucleus of both astrocytes and neurons in the adult brain. The ADK expression profiles depicted here are schematic representations based on Western blot analyses from previously reported publications (Bjursell et al., 2011; Boison et al., 2002; Cui et al., 2011).