Oncogenic Ras pushes (and pulls) cell cycle progression through ERK activation.

The Ras-Raf-MEK-ERK signaling cascade is capable of channeling a wide variety of extracellular signals into control of cell proliferation, differentiation, senescence, and death. Because aberrant regulation at all steps of this signaling axis is observed in cancer, it remains an area of great interest in the field of tumor biology. Here we present evidence of the intricate and delicate levels of control of this pathway as it pertains to cell cycle regulation and illustrate how this control is not simply a rheostat.