HSF1 and esophageal squamous cell carcinoma: ESCC patients with a combined low expression level of HSF1 both in tumor cells and stromal cells had the longest DFS and OS, whereas the patients with a single high expression level of HSF1 in stromal cells had the shortest DFS and OS, suggesting that the levels of HSF1 activation both in tumor cells and stromal cells and, especially, in stromal cells could improve the ability to predict patient outcome.