HSF1 and neoplasm: Loss of tumor suppressor abilities of the wild-type p53 protein results in oncogenesis, whereas proper HSF1 action, though non-oncogenic itself, actively supports this process.<h4>Conclusions</h4>Here, we describe in detail the interplay between the p53 and HSF1 signaling pathways, with particular emphasis on the molecular mechanisms involved, as well as their importance for normal cellular behavior, cancer development, the effectiveness of anti-cancer therapies and their toxicity.