Protein Kinase Inhibitors for the Treatment of Disease: The Promise and the Problems -- General Aspects of PKs Inhibition -- New Design Strategies for Ligands That Target Protein Kinase-Mediated Protein-Protein Interactions -- Pharmacological Potential and Inhibitors of Individual Classes of Protein Kinases -- The Paullones: A Family of Pharmacological Inhibitors of Cyclin-Dependent Kinases and Glycogen Synthase Kinase 3 -- Pharmacological Potential of p38 MAPK Inhibitors -- Inhibitors of PKA and Related Protein Kinases -- Inhibitors of Protein Kinase CK2: Structural Aspects -- Aminoglycoside Kinases and Antibiotic Resistance -- Pharmacological Potential and Inhibitors of Individual Classes of Protein Phosphatases -- Protein Tyrosine Phosphatases as Therapeutic Targets -- Structure-Based Design of Protein Tyrosine Phosphatase Inhibitors -- Biological Validation of the CD45 Tyrosine Phosphatase as a Pharmaceutical Target -- Serine/Threonine Protein Phosphatase Inhibitors with Antitumor Activity -- Inhibitors in Clinical Use or Advanced Clinical Trials -- Clinical Immunosuppression using the Calcineurin-Inhibitors Ciclosporin and Tacrolimus -- Targeted Therapy with Imatinib: An Exception or a Rule? -- Clinical Aspects of Imatinib Therapy -- Isoquinolinesulfonamide: A Specific Inhibitor of Rho-Kinase and the Clinical Aspect of Anti-Rho-Kinase Therapy -- Discovery and Development of Iressa: The First in a New Class of Drugs Targeted at the Epidermal Growth Factor Receptor Tyrosine Kinase.The aims of this volume are to highlight the tremendous pharmacological potential of protein kinase and protein phosphatase inhibitors, to provide a thorough overview of the most remarkable achievements in the field and to illustrate how beneficial these studies can be for the advancement of both basic knowledge on biological regulation and deregulation and for the clinical treatment of a wide spectrum of diseases. This goal is attained by contributions of leader investigators in the field, who address the issue from different angles.