For the first time, researchers at the University of Toronto have mapped out the genes that keep our cells alive, giving us a better grasp on how our genome works, according to Phys.

As outlined in their study, they switched off 90 percent of the human genome one by one - totaling almost 18,000 genes -  and found the ones that were essential for cell survival, something that scientists can use to determine which genes are crucial in diseases such as cancer.

According to the researchers, there are more than 1,500 genes that are essential for human survival. In addition, they also discovered the sets of genes in cancer cell lines that tumors rely on. These findings can help scientists create drugs that target specific genetic lines and inhibit tumor growth.

"It's when you get outside the core set of essential genes, that it starts to get interesting in terms of how to target particular genes in different cancers and other disease states," said Jason Moffat, co-author of the study.

The researchers used CRISPR technology, a gene editing technology that makes it possible to turn genes on and off and determine the far-reaching effects that these switches have on the human body.

"We can now interrogate our genome at unprecedented resolution in human cells that we grow in the lab with incredible speed and accuracy," said Moffat. "In short order, this will lead to a functional map of cancer that will link drug targets to DNA sequence variation."

In the study, Moffat and his team used metformin, a common diabetes drug, to kill brain cancer and colorectal cancer cells, as well as various antibiotics to kill another form of colorectal cancer. These results show how the genomic information can be used to determine specific drugs that are effective at killing specific kinds of cancers.

"The Moffat group has developed a powerful CRISPR library that could be used by investigators around the world to identify new treatment strategies for the treatment of cancer," said Aaron Schimmer, a medical oncologist at Princess Margaret Cancer Centre, who was not involved in the study. " I would be interested in using this tool to identify new treatment approaches for acute myeloid leukemia - a blood cancer with a high mortality rate."