UCA1 and esophageal squamous cell carcinoma: UCA1, which also functions as a tumor promoter in breast cancer, colorectal cancer, gastric cancer, and esophageal squamous cell carcinoma [15–18], is closely related to the prognosis of a variety of cancers; for example, Han et al. found that high UCA1 expression indicated worse prognosis in colorectal cancer [16].