This paper studies efficient and optimal auction design where bidders do not know their values and solicit advice from informed but biased advisors via a cheap-talk game. When advisors are biased toward overbidding. we characterize efficient equilibria of static auctions and equilibria of the English auction under the NITS condition (Chen. Kartik and Sobel (2008)). https://herbsdailyes.shop/product-category/bitter-melon/