HSP90AA1 and cancer: In cancer cells, Hsp90 is upregulated, and many oncogenic proteins (for example c-Abl, c-Raf, b-Raf, c-Src, Cdks, cyclins, mutant p53, Stat3, steroid receptors) rely on the chaperoning functions of Hsp90 for their folding, maturation, and activation [153–156].