What are gene expression levels?

Gene expression levels are how much genes are working inside your body, like a factory line deciding how many toys to make each day.

Imagine your body is a big toy factory. Each gene is like a special robot that makes one kind of toy, say, a car or a doll. Now, some days the factory wants to make lots of cars, and other days it switches to making dolls. That’s like how gene expression levels change: they tell your body how many toys (or proteins) each robot should make.

Think of a gene as a recipe for a cookie. If the kitchen is really busy, the chef might bake more cookies, that's higher expression level. But if it’s slow, they only make a few, that's lower expression level.

Your body uses these levels to decide what happens next: growing taller, fighting off a cold, or even changing color like some animals do! It's all about how much each gene is working at any given time.