Unlike many tissues, hair regenerates multiple times during the life of an individual. The external hair is composed of dead cells that have undergone a process of differentiation. The linear growth of hair represents different stages of hair development such as the tip of the hair shaft contains the earliest cells that were produced during the new regenerative phase and the base of the hair shaft contains the most recent cells. New RNA-sequencing technologies developed by many California based companies provided us a new way to study these cells. In this study, we discovered that the history of these hair cells could be analyzed using RNA sequencing. The approach allow us to understand what genes are activated in cells which are just beginning regeneration of the hair and which genes are activated when the hair ceases to grow. This discovery may have important implications for understanding hair disease in addition to many systemic diseases that may affect hair.