What 2 general steps follow the reception of a signalling molecule (ligand)?

Question

I don’t know if this is useful, but the question said: nerve growth factor is a water-soluble signalling molecule.

Answer 1

Generally, if it's water soluble, it means it cannot readily diffuse across the lipid membrane. That said, nerve growth factor, given its name, would most likely bind to its specific receptor and cause an signal transduction cascade that would result in growth of nerve cells.

There are a couple of ways that could happen, and depending on what you're learning in the class the professor can be hinting at how they want you to answer that question.