The present invention is directed to novel uses of a polynucleotide sequence of a novel G-Protein Coupled Receptor 5HT6. The invention also provides the human 5-HT6 receptor as being associated with hematological disorders, pain diseases, respiratory diseases, genito-urological disorders, cardio vascular diseases and cancer. The invention also provides assays for the identification of compounds useful for the modulation of hematological disorders, pain diseases, respiratory diseases, genito-uro-logical disorders, cardio vascular diseases and cancer for treating or preventing hematological disorders, pain diseases, respiratory diseases, genito-urological disorders, cardio vascular diseases and cancer associated with expression of the 5-HT6 receptor.