Molecular and functional diversity of the TRPC family of ion channels. TRPC channels and their role in ROCE/SOCE -- Functional Rescue of Misfolded Receptor Mutants -- Obesity-related mutations of leptin and melanocortin receptors -- cAMP- and cGMP-dependent control of lipolysis and lipid mobilization in humans: putative targets for fat cell management -- Central Neuropeptide Receptors Involved in Water Balance: Application to Apelin -- Targeting regulators of G protein signaling (RGS proteins) to enhance agonist specificity -- Dimeric GPCRs: what did we learn from the metabotropic glutamate receptors? -- Guiding principles applied in the design of GPCR-selective hypothalamic hormone agonists and antagonists -- Mutations in G proteins and G protein-coupled receptors in human endocrine diseases -- A molecular dissection of the glycoprotein hormone receptors -- Receptor Tyrosine Kinases as Targets for Cancer Therapy Development -- Targets for pituitary tumor therapy -- The endogenous cannabinoid system in the control of food intake and energy balance. G-Protein Coupled receptors (GPCRs) and other receptors are significant targets for drug discovery, due to their roles in fundamental physiological processes. Among these roles are: regulation of growth, food intake, reproduction, water balance, sensory perception, blood pressure and heart rate. GPCR-directed drugs account for approximately $40 billion in sales and, of drugs at market, approximately 70% target GPCR function. The availability of combinatorial chemistry coupled with high throughput screening techniques have facilitated discovery of peptidic and non-peptidic ligands of membrane receptors. Mutant receptor models have revealed their role in health and disease and provided insight to new therapeutic approaches, based on control of protein trafficking. Understanding receptor-receptor interactions has provided one mechanism for receptor cross-talk and revealed unexpected interactions. The completion of the human genome has identified a new source of therapeutic targets: "orphan receptors" with unknown functions and yet-to-be discovered ligands. Some orphans have now been identified as ghrelin, nociceptin, apelin, and urocortin. This finding, along with important technologies to develop ligands with desirable characteristics, including peptidomimetics is likely to further accelerate interest in this area.