Since Hsp90 was identified as a potential cancer target, various inhibitors targeting cytoplasmic Hsp90 have been established as anticancer agents [73,142,143], and many different inhibitors with desirable pharmacological properties, including ganetespib (STA-9090), have been evaluated in clinical trials, but none have shown satisfactory efficacy to be approved by the FDA. Here, HSP90AA1 is linked to cancer.