Deguelin seems to form crucial interactions with Ser677 and Lys615 of HSP90 CTD, disrupting HSP90 function of binding nucleotide.452 A study in vivo showed that deguelin significantly reduced cancer growth by decreasing the expression of HSP90 clients, with no observable toxicity.453 The latest discovered derivative, HVH-2930, fits into the CTD ATP-binding pocket interface cavity of the HSP90 homodimer, which stabilizes the open conformation of HSP90 and hinders ATP binding. Here, HSP90AA1 is linked to cancer.