And in this particular case, this gene is for the enzyme we call galactose one phosphate urigal transphrase. And we'll see what it does in just a moment. And in individuals who have classic galactosemia, this gene or both of these genes are actually mutated. And what that means is these individuals cannot actually form a functional enzyme. And what that means is if this enzyme isn't actually formed or is dysfunctional, what that means is it can carry out a specific type of function. Now this enzyme is actually an important enzyme that is involved in the galactose glucose interconversion pathway that we focused on in detail in the previous lecture.