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.