Mitogen-Activated Protein Kinases (MAPKs): Activation, Functions and Regulation opens with a summary of the present knowledge about MAPK, with special emphasis on p38 and c-Jun N-terminal kinase. The authors focus on how these signaling pathways are engaged during some infections with intracellular parasites. The authors also describe selected regulatory aspects of circadian clocks in vertebrates, exploring an intriguing link to MAPK. Circadian clocks are time-tracking systems that provide organisms with a survival advantage. Cadmium, one of the toxic metals, is an important occupational and environmental pollutant that damages various organs, especially the kidney. The concluding study proposes that the type of kidney cell and severity of cadmium-induced cellular stress appear to determine the effect of MAPK on cell fate.