Your diagnosis

About ALK


If you have been told that you have ALK+ NSCLC, you might be wondering what this means.

Firstly, NSCLC stands for 'non-small cell lung cancer' – you can learn more about what this is here. About 85% of people with lung cancer have NSCLC.1

To understand what ALK+ means, we need to learn a bit more about 'DNA'.

Your body is made up of trillions of tiny building blocks called cells. Inside each cell is DNA. DNA is like a set of instructions that tell your cells what to do. They tell the cell to make certain things, when to grow or multiply, when to move around, and even when it is time to die.2

Normally your DNA helps keep your cells in a careful balance,3 so that they are multiplying and dying at a similar speed. But sometimes something goes wrong, and the DNA changes. This can cause cells to grow too fast and eventually make a tumour.2

ALK+ means that you have a change in a small part of your DNA (the small part is called a ‘gene’) that makes a protein called ALK (or 'anaplastic lymphoma kinase'). This protein is responsible for a few different things, including telling cells to grow and multiply, and move around.4,5

ALK doesn’t exist in healthy lungs – your cells would normally ignore that bit of information in your DNA. But in ALK+ NSCLC, the change in the gene means that your lung cells start making the ALK protein. When this happens, your cells start to grow and multiply out of control, and eventually they build up and become tumours.6–9

You can learn more about how changes to your ALK gene can cause NSCLC with the diagram below:

In a cell from ALKNSCLC, the gene for ALK somehow becomes changed.

Because the gene has changed, it becomes known as ALK+ (ALK-positive).

The changed ALK+ gene contains altered instructions, which create an altered version of the ALK receptor.
Once it’s sat on the surface, the altered ALK receptor cannot control all the messages coming in.
The cells with the ALK+ receptor end up being bombarded with messages telling the cells to grow and multiply, forming tumours, which may begin to spread around the body.
Only about 5% of people with NSCLC (1 in 20) have a change in their ALK gene.1 We don’t know exactly what causes the DNA to change in somebody with ALK+ NSCLC, but you can learn more about some risk factors for lung cancer further down this page.

Click on one of the options below to learn more 

Anaplastic lymphoma kinase
Deoxyribonucleic acid
Non-small cell lung cancer

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