The main problem is the old idea, that the message is the messenger. In a way that is still true, but its not one message per messenger molecule. The message i

The main problem is the old idea, that the message is the messenger. In a way that is still true, but its not one message per messenger molecule. The message is intimately connected to what other messenger molecules are around, what are they bound too, what composition of receptors are on the cell surface, what are those receptors connected to, what secondary messages are being sent intracellularly and what messages have the cells received previously. As we have understood the hormones passing loud, clear and overruling messages (like e.g insulin and thyroid hormone) we start discovering the much more specific and context-dependent hormones. And those are going to have effects that are much more dependent on the cellular state, and so are much more difficult to understand. It's extremely complex, because the state of the cellular machinery is huge, and quite a lot of things we can't really observe directly.