Upon β-ionone binding, OR51E2 reduces the proliferation of prostate cancer cells by causing phoshorylation of stress-activated protein kinase/c-Jun NH2-terminal kinase (SAPK/JNK) and p38 and promotes invasiveness of prostate cancer cells through Gβγ–PI3Kγ pathway [19,111]. This evidence concerns the gene MAPK8 and prostate cancer.