Dr Lin seems very knowledgeable about the immune system and takes his time explaining how it works and your test results as well. I felt very confident in his recommendations and followed the plan he designed for me. However I am looking for another doctor based solely on the fact that he is completely unresponsive to phone calls or emails requesting a return call or answer to email. It is impossible to difficult to actually reach someone in his office as usually there is an answering service that takes messages. And there is no response from messages left. I discussed this issue with Dr Lin during my last office visit. But there has been to change noted in the lack of communication since then. Therefore I am looking for a new doctor and would not recommend Dr Lin.