Dr. Thomas Klein
The search results provided do not contain information about Dr. Thomas Klein's specific experience or educational background in hair transplantation. The information available pertains to a Dr. Thomas Klein who is a radiation oncologist and another Dr. Thomas Klein who has a history of work in the LGBT community and healthcare, particularly concerning AIDS. Neither of these profiles mention hair transplantation or the clinic website you provided. Therefore, I cannot provide a summary of Dr. Thomas Klein's background in hair transplantation based on the given search results.