other secretory epithelia. Cystic fibrosis transmembrane conductance regulator (CFTR) is the mutated gene and is essential to chloride and bicarbonate secretion. The abnormal amount of anion secretion causes a reduced amount of ductal water flow. Because of this, the duct’s protein concentration increases and causes the duct lumina to get plugged. The onset of cystic fibrosis affects the pancreas more than any other organ (even before birth). Pancreatitis The incorrect activation of proteolytic enzymes leads to edema, inflammation, and possible pancreas necrosis, causing acute pancreatitis. The most prominent cause of acute pancreatitis is gallstones. Permanent damage is possible from chronic pancreatitis due to progressive inflammation and the reoccurrence of acute pancreatitis. Acute pancreatitis is caused by mutations in a trypsinogen inhibitor, while a mutation in CFTR causes chronic pancreatitis. In fact, chronic pancreatitis often causes pancreatic adenocarcinoma. Pancreatic ductal adenocarcinoma Pancreatic Ductal Adenocarcinoma (PDAC) is one of the most lethal cancers and has an expected survival of five years. Pancreatic adenocarcinoma cells resemble pancreatic ductal cells. Both cell groups show tubule formation, cuboidal shape, and ductal markers. Additionally, acinar and endocrine cells have often been found in many of these cancers, demonstrating plasticity and the possibility that the initial target cells are pancreas progenitor cells. Moreover, human tumors usually go with lower-grade lesions that are called pancreatic intraepithelial neoplasias (PanINs) and are in ducts. Because these lesions are in ducts, this means that it is possible that the beginning target cells are ductal cells. Breast ductal carcinoma Ductal carcinoma in situ (DCIS) is the proliferation of malignant ductal cells without penetrating the stromal tissue around them. In other words, DCIS is the presence of abnormal cells in a breast’s milk duct. It is thought to be the earliest form of breast cancer and is noninvasive (it has not spread from the milk duct and has a low risk of becoming invasive). DCIS can be differentiated into groups based on low, intermediate, and high grade. When comparing the growth potential of normal epithelial cells to DCIS, it is 10 times larger, and the apoptosis rate was also 15 times greater. Furthermore, comedo-type DCIS usually causes necrosis in the duct center and has a more significant threat of reappearance. The majority of ductal carcinomas are positive for luminal cell markers (CK8, CK18, CK19) but negative for basal cellmarkers (CK5/6 and CK14). In 30% of cases, DCIS is multifocal and usually is in