Krishnamurti Dakshinamurti & Janos Zempleni 
Nutrients and Cell Signaling [PDF ebook] 

Cell signaling is at the core of most biological processes from the simplest to the most complex. In addition to unicellular organisms possessing the essential ability to receive inputs with regard to nutrient availability and noxious stimuli, the cells in multicellular organisms require signaling from adjacent, as well as distant cells to maintain