HuR/ELAV1 is an RNA-binding protein and a member of the embryonic lethal abnormal vision (ELAV) protein family. The protein is ubiquitously expressed in normal tissues and posttranscriptionally regulates mRNA targets (numbering in the thousands) with AU-rich elements (ARE). Upon acute stress, activated HuR/ELAV1 moves from the nucleus to the cytoplasm with its mRNA cargo and affects gene expression of its targets by influencing mRNA stability or facilitating protein translation. Cancer cells exploit HuR/ELAV1 biology by upregulating the HuR/ELAV1 pro-survival network (e.g., anti-apoptosis, DNA damage repair, cell cycle progression, and other tumorigenic pathways), particularly in response to acute stressors like hypoxia, nutrient deprivation, or chemotherapy. Clinicopathologic studies in different cancer types demonstrate that increased cytoplasmic expression of HuR/ELAV1 is associated with aggressive pathologic features and poor prognosis.