Key environmental signals that act as inputs are coloured red. Proteins are coloured green with connections indicated by arrows; solid for positive regulators and dashed lines for negative regulators. The five polycistronic operons of the LEE are coloured blue. Abbreviations: NAG/NAG 6-P: N-acetylglucosamine and N-acetylglucosamine 6 phosphate; Epi/NorEpi: epinephrine and norepinephrine.