The 90 kiloDalton heat shock protein (Hsp90) is broadly relevant to almost all human cancers. These include common cancers like breast cancer but also rare childhood cancers of the blood and brain. Hsp90 is a molecular chaperone that is critical for supporting the elevated and aberrant activities of a myriad of factors like kinases and transcription factors that drive the development and progression of cancer. Hsp90 is also plays a central role in dieseases like cystic fibrosis (CF). The loss of the cystic fibrosis transmembrane conductance regulator (CFTR) causes CF. The CFTR protein is entirely dependent on Hsp90 to fold into a functional conformation. Altering Hsp90 function can restore the folding and function of disease-causing mutant forms of CFTR. Specifically reducing the amount of a key Hsp90-regulating protein called Aha1 can restore the function of the most common disease variant of CFTR, deltaF508. Understanding how Hsp90 function is regulated by Aha1 will lead to treatment strategies for diseases like CF.