In this talk we explore the converse: We will give a brief characterization of when a Lie group has a Lie isomorphic group which is definable in an o-minimal expansion of the real field, and concentrate then on when Lie isomorphisms, hopefully focussing on two questions: - That any Lie isomorphism between definable groups can be added to the language without losing o-minimality and - Give a brief overview and some interesting open questions about "non definable Lie isomorphic definable groups".