In our work, we identified that Hsp90A, the major Hsp90 form, is downregulated in ALDH+ CSCs compared to the majority of cancer cells, which are known to rely on high levels of HSP90 activity, including post-translational modifications that promote Hsp90 binding to the co-chaperone STIP1 and inhibit binding to CHIP to increase protein folding and stabilization [56]. This evidence concerns the gene HSP90AA1 and cancer.