GPR12 and neoplasm: In addition, Hematoxylin-Eosin (HE) staining and TdT-mediated dUTP-biotin nick end labeling (TUNEL) staining showed that GPR12 knockdown significantly increased the tumor necrotic area (Figure 4D) and the number of apoptotic cells in the tumor tissues of mice compared with scramble group, respectively (Figure 4E).