An important function of our cells' signaling pathways is to coordinate growth with environmental cues, such as the availability of nutrients in the cell's environment. Cell growth plays an important role in normal cell function—for example, building muscle in response to exercise— and it also goes awry in diseases such as cancer. The protein complex GATOR2 plays an important role in sensing and relaying information to the mammalian target for rapamycin complex 1 (mTORC1), an assembly of proteins that together control cell growth in response to environmental conditions. Through protein complexes such as GATOR2, mTORC1 senses nutrient levels in the cell, and either stymies or promotes growth accordingly. In a paper published July 13 in Nature, Whitehead Institute postdoc Kacper Rogala and Massachusetts Institute of Technology (MIT) graduate student Max Valenstein reveal the structure of GATOR2 and offer a glimpse into its function. This research was done in the lab of former Whitehead Institute Member David Sabatini.