OR51B5 and prostate cancer: For instance, in the prostate cancer cell line LNCaP and in primary prostate cancer cells, β-Ionone-induced OR activation caused an ~40% inhibition of cell proliferation.6 Similarly, another study reported a reduction in hepatocarcinoma cell proliferation mediated by the (−)-citronellal-induced activation of OR1A2.7 According to our investigations in hepatocarcinoma cells, the OR51B5-mediated increase in intracellular Ca2+ and MAPK phosphorylation is responsible for changes in various physiological processes.