MAP kinases: from intracellular signals to physiology and disease.

Although differentiated cells will usually maintain their specialized character, conversion of cellular specificities can be observed during adaptation or reparative regeneration. In pathological conditions, such as inflammation and carcinogenesis, even highly specialized cells can alter their properties, leading to a deranged control of cell differentiation and/or proliferation. Mitogen-activated protein kinases are central regulators of these processes.