Signal transduction therapy has become recently a leading area of modem drug research aiming to inhibit and modulate the pathomechanism based validated target molecules in intercellular and intracellular signaling.Proliferation of infected,damaged or malfunctioning cells is very often a key factor in the generation of the pathological state, not only in cancer and infectious diseases but also in inflammation or autoimmune related diseases.Signals of intercellular communication are mediated from the cell surface to the nucleus by a cascade of phosphorylation events, involving the interaction of a big series of proteins: a network, that monitors the environment of the cell and co-ordinates its responses.The malfunctioning network of supporting signals within tumour cells present multiple targets for pharmaceutical interception, which is the basic idea of signal transduction therapy.Selective inhibition of these false proliferative signals via targeting receptor tyrosine kinases and other signaling enzymes, resulting in the induction of apoptosis by depletion of the "survival factors"is one of the most studied and widely accepted concept of modem chemotherapy.