TYR and hydrops fetalis: In this study, histological analyses were performed to label the FMs and MSCs using tyrosinase (Tyr) and CD34 in mouse treated skin, and results showed that TCQA upregulated Tyr expression in the epidermis and along the HF especially in the bulb region, and this correlates with the activation of FMs and the production of melanin during the anagen phase of the hair cycle (Figure 1F).