HSPA1A and cancer: Molecular chaperones such as HSP70 help cancer cells, notably the CSC subpopulation, to adapt to hostile environmental stresses such as hypoxia, nutrient deprivation, and oxidative stress, as well as to overcome these severe conditions by catalyzing the proper folding of nascent proteins and the refolding of denatured proteins, and thus are considered to be central to the adaptive cellular response contributing to maintaining the cell viability.