RETREG1 and esophageal squamous cell carcinoma: FAM134B’s role in various malignancies, including ESCC [3, 8], colorectal cancer (CRC) [9, 10], breast cancer [11, 12], and HCC [13, 14], is well-documented, with its function varying from an oncogene in ESCC and HCC to a tumor suppressor in CRC and breast cancer.