Critically, Hsf1 is frequently activated in cancer cells: it has been shown to be required for cancer progression in animal models (Dai et al., 2007), its activation is associated with poor prognosis in many human cancer patients (Santagata et al., 2011), and it drives cancer-specific gene expression programs in both tumor cells and the supporting stroma (Mendillo et al., 2012; Scherz-Shouval et al., 2014). This evidence concerns the gene HSF1 and cancer.