General Biochemical and Morphological Aspects.- Historical Development of the Receptor Concept.- Classification of Cell Receptors.- Biochemical Characterization of Cellular Hormone Receptors.- Morphological Characterization of Cell Receptors.- Molecular Biology of Receptors for Neuropeptide Hormones.- Cell Surface Receptors.- Peptide Hormone Receptors.- Growth Factor Receptors.- Low-Density Lipoprotein Receptors.- Neurotransmitter Receptors in Human Brain Diseases.- Lectin Receptors.- Cytosolic/Nuclear Receptors.- Steroid Hormone Receptors.- Oncogene and Receptor Expression.- Oncogene and Receptor Expression.- Special Aspects of Tumor Pathology.- Breast Carcinoma.- Prostatic Cancer - Immunohistochemistry of Steroid Hormone Receptors.- Lineage-Specific Receptors in the Diagnosis of Malignant Lymphomas and Myelomonocytic Neoplasms.