Within every living cell, a molecular gatekeeper decides when to grow and when to rest — a decision that, when corrupted, becomes the engine of cancer. Researchers at KAIST and Yonsei University have now traced the precise molecular handshake that flips this switch, revealing how a protein called LARS1 escapes its resting complex when amino acids are plentiful and carries the signal that tells cells to multiply. The discovery does not yet offer a cure, but it offers something perhaps more durable: a map of the mechanism, and with it, a more precise target for therapies that could one day spare