An estimated 170,000 Australians were diagnosed with cancer in 2025.

Many people know the causes of cancer are partly genetic. But how do your genes, which contribute so much of what makes you you, change what they do and cause a cancer?

Where do these “cancer genes” come from? And are they ticking time bombs?

Cancer is caused by DNA mutations

DNA is called the “instructions for life”, but what does it do? Your cells can read DNA like an instruction manual, and use those instructions to make proteins. The section of DNA with the instructions for a particular protein is called a “gene”.

A cell is like a tiny machine, and proteins are the cogs and gears that keep everything running smoothly – that is, keeping your cells healthy and functioning normally. There’s a protein for every job in a cell.

But what happens if there is a mistake in the instruction manual – a DNA mutation?

Incredibly, cells have proteins whose job it is to identify and fix DNA mutations. But if a DNA mutation can’t be repaired, a cell might make too much or too little of a certain protein, or maybe a protein that doesn’t actually work.

So, a common pathway to cancer is when a protein responsible for fixing DNA........

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