One says that there is an 'interaction' between the moderator and the predictor, not between the mediator and the predictor, as you are doing.

To make the example of a mediator let us assume that:

Obesity (the predictor) increases the risk for diabetes (what you call the response).

Now you might ask, what is the mechanism underlying this (supposed) causal relationship? One hypothesis is that insulin resistance mediates this relationship, that is, is the mediator. Obesity increases insulin resistance, which in turn increases the risk for diabetes. There needs to be no interaction between obesity and insulin resistance. Obesity remains a predictor both for insulin resistance and diabetes. Insulin resistance might provide a deeper/biological understanding of how/why obesity increases the risk for diabetes.

In this context, an example for a mediator could be genes.

There might be some specific genes, such that if one person has them, despite being obese the risk for diabetes is not increased. In this case, one speaks of an interaction between obesity (the predictor) and genes (the moderator).

Hope this helps.

One says that there is an 'interaction' between the moderator and the predictor, not between the mediator and the predictor, as you are doing.

To make the example of a mediator let us assume that:

Obesity (the predictor) increases the risk for diabetes (what you call the response).

Now you might ask, what is the mechanism underlying this (supposed) causal relationship? One hypothesis is that insulin resistance mediates this relationship, that is, is the mediator. Obesity increases insulin resistance, which in turn increases the risk for diabetes. There needs to be no interaction between obesity and insulin resistance. Obesity remains a predictor both for insulin resistance and diabetes. Insulin resistance might provide a deeper/biological understanding of how/why obesity increases the risk for diabetes.

In this context, an example for a moderator could be genes.

There might be some specific genes, such that if one person has them, despite being obese the risk for diabetes is not increased. In this case, one speaks of an interaction between obesity (the predictor) and genes (the moderator).

Hope this helps.