Tumor marker

Okay, so you know how sometimes doctors have to look inside our bodies to see what's going on? They use fancy machines like x-rays and scanners to help them see the inside of our bodies.

Now, sometimes when we get sick, our bodies start making things that doctors can see in our blood or other body fluids. These are like little flags that tell the doctors that something might be wrong. When doctors find these flags, they call them "tumor markers" because they can sometimes mean that we have a lump called a tumor in our bodies.

Tumor markers help doctors figure out if we have cancer or not. So, if the doctors find a tumor marker in our blood or other body fluids, they might do some more tests to see if we have a lump in our body that needs to be treated.

It's important to remember though, just because a doctor finds a tumor marker in our body, it doesn't always mean we have cancer. Sometimes, our body just makes these flags when we're sick in other ways too.