MKI67 and pancreatic intraductal papillary-mucinous neoplasm: KL−6 measurement [17], immunostaining for factors such as Ki−67, p53, and MUC using a cell block method [10], and liquid-based cytology for pathological specimen treatment have been shown to improve the sensitivity [3]; however, despite the use of these methods, the diagnostic ability of PJC for malignant IPMN remains insufficient.