PTGS2 and breast carcinoma: Chen et al. (2017) showed that in MB-231 breast cancer cells, bufalin (1 μM) could stimulate the inflammatory reaction induced by TPO, a protein kinase C (PKC) activator, leading to significantly higher levels of cyclooxygenase-2 (COX-2) and IL8, two inflammatory markers, and thereby a higher level of prostaglandin E2 (PGE2), which work together to stimulate MB-231 cell proliferation and invasion (Chen et al., 2017).