In contrast to observations mentioned above that 5-HT and its receptors positively regulate tumor progression, one study revealed that the 5-HT/HTR1E signaling attenuated by chronic stress resulted in higher levels of cell proliferation and epithelial mesenchymal transition of ovarian cancer cells, thereby promoting tumor growth and peritoneal dissemination 30. The gene discussed is HTR5A; the disease is ovarian carcinoma.