Description: "This animation describes how growth factors bind to a membrane-bound receptor and triggers a cascade of downstream transduction processes.Cell behavior is governed by the effects of growth factors which interact with membrane-bound glycoprotein receptors that transduce the first message into a series of intracellular signals that in turn promote or inhibit the transcription expression of specific genes. Cancer cells adopt two principal signaling strategies between cells: endocrine signaling and paracrine signaling. Aside from growth factors, lipophilic hormones such as steroids and thyroid hormone are potent regulators of cell behavior, and may cancers are either hormone-dependent or are responsive to hormone therapy. In the prevention of breast cancer, steroid hormone analogs such as tamoxifen are used to mimic the action of the natural estrogen, eliciting a much weaker estrogenic response. This animation is general in scope, so it can be used in various different lecture contexts"