CEACAM5 and cyst: Moreover, EUS provides a better characterization of the structure of the cyst and allows one to evaluate the cystic fluid and determine cytology, amylase levels, carcinoembryonic antigen (CEA) levels, and, if possible, diagnostic molecular markers (KRAS, GNAS, VHL, and CTNNB1) and prognostic molecular markers (TP53, PIK3CA, and PTEN), rendering ultrasound endoscopy as a potential essential tool for the proper diagnosis of pancreatic cysts [6,7,8].