Fig. 1
From: Cancer metastasis: enactment of the script for human reproductive drama
A simplistic version of the expanded HPG axis in Human and cancer reproduction. The axis is expanded to include prolactin, oxytocin and the activing-inhibin axis as well as non-traditional actions such as the extrapituitary actions for GnRH and extragonadal actions for FSH and LH. Complex feedback and interactions among the axis members are omitted for simplicity. HPG hypothalamus–pituitary–gonad, GnRH gonadotropin releasing hormone, FSH follicle stimulating hormone, LH luteinizing hormone, HCG human chorionic glycoprotein