Stanford University researchers have found a “dimmer switch” that stops a gene from sending protein signals that promote cancer.

When the Myc gene makes too much of the protein Myc, cells lose the ability to kill themselves when they’re damaged, and instead keep growing. The researchers found that by turning down the Myc switch, they could shrink tumor cells to normal sizes and restore their ability to die.

Previously, it had been thought that the Myc gene had to be turned off entirely to stop cancer. Since low levels of Myc are needed for normal cell functions, Myc couldn’t be a target for cancer treatment. The research now means that Myc and similar cellular signals can be a target for therapy.

Problems with Myc contributed to the cancer-related deaths of as many as 70,000 Americans each year.