RETREG1 and esophageal squamous cell carcinoma: Family with sequence similarity 134-member B (FAM134B) was firstly found in esophageal squamous cell carcinoma and encodes a 497 amino acid CIS Golgi transmembrane endoplasmic reticulum receptor protein, which regulates the turnover of endoplasmic reticulum through selective phagocytosis and affects the endoplasmic reticulum stress of cells [14–16].