[Hair follicle bulge cells]

Hair follicles reconstitute themselves though the hair cycle, suggesting the presence of stem cells. Slow-cycling cells were found in the bulge area and were considered as stem cells of the epidermis. Multiple studies have constantly demonstrated that bulge cells possess stem cell properties such as high proliferative capacity and multiple potencies to regenerate into not only hair follicles but also sebaceous glands and epidermis. Recently, the knowledge of the bulge cell biology is rapidly increasing along with the identification of novel cell surface markers, the ability to isolate living bulge cells, and the microarray analysis of multiple gene expression.