Lactate jump-starts mTORC1 in cancer cells

The kinase mammalian target of rapamycin ( mTOR ) is a major regulatory hub that senses and integrates nutrient, energy, and growth factor inputs to promote cell growth. In this issue of EMBO Reports , Byun et al [1] report that high intracellular levels of lactate activate mTORC 1 in KRAS transformed cells independently of a growth factor input. This suggests a mechanism for how mTORC 1 can be co‐opted to support oncogenic growth and proliferation.