GnRH analog activities at the pituitary level (activation of the pituitary-gonadal axis) significantly differ from those at the cancer cell level (inhibition of cancer cell growth and metastatic behavior) suggesting that, according to the cell context, GnRH-R can be coupled to different G proteins and, therefore, to specific intracellular signaling pathways and molecular transducers [14,15,16,20,37,42,44,45,137,140,155,156]. Here, GNRHR is linked to cancer.