However, other emerging factors, such as the unfolded protein response (UPR) activation following endoplasmic reticulum (ER) stress and GRP78 (also known as BiP or HSPA5) overexpression and/or localization, have been recently described to affect not only EC cells growth and invasiveness but also their ability to survive both the hostile tumor microenvironment and the aggression of chemotherapeutic agents. The gene discussed is HSPA5; the disease is neoplasm.