The present invention describes two newly discovered Human Leucine Rich Repeat (LRR)-containing proteins, HLRRNS-2 and HLRRNS-3, and their encoding polynucleotides. Also described are expression vectors, host cells, agonists, antagonists, antisense molecules, and antibodies associated with the polynucleotides and/or polypeptides of the present invention. In addition, methods involving the new HLRR-containing proteins HLRRNS-2 and HLRRNS-3, or modulators thereof, for treating, diagnosing, preventing, and screening for disorders associated with aberrant cell growth, neurological conditions, and diseases or disorders related to the brain are illustrated.