If you are 'prone' to something it means you have a natural inclination or tendency towards something. Being 'prone to' or 'susceptible to' something can mean that you are vulnerable and likely to suffer from a particular setback or demonstrate particular negative characteristics. You might be 'prone to hayfever' or 'prone to headaches' for example or be 'prone to becoming frustrated'. If you are 'susceptible' to something it means you are easily influenced or harmed by something or somebody. Your boss might be 'susceptible to suggestions' or 'susceptible to flattery' for example. The adjective susceptible is usually used to describe someone or something who is easily influenced.

1. I'm not sure how much I can believe Alice's story because she is prone to exaggeration.
2. Paul is very susceptible to flattery. If I ever want something from him, I just pay him a compliment.
3. These type of plants are very susceptible to frost so I keep them indoors during the winter.

1. The boss is prone to bouts of anger if something doesn't go his way. I don't think that's how someone in authority should behave.
2. I have noticed that I am prone to bias like most people though I take a number of measures to keep it in check.
3. Our system is currently susceptible to a security breach if we don't take steps to rectify it immediately.