Provided herein is a relatively pure population of mesenchymal stem cells (MSCs) expressing the Notch 2 receptor (Notch 2+ MSCs). Also provided is a method of isolating from a subject a population of Notch 2+ MSCs and a method of culturing the population of Notch 2+ MSCs. Also provided is a method of treating a subject with a disorder associated with a deficiency or defect in cells of mesenchymal lineage comprising administering a population of Notch 2+ MSCs to the subject.