THY1 and familial pancreatic carcinoma: In addition to PDAC, we investigated the expression of CD90 in malignant pancreatic neuroendocrine tumor (PNET) and adenosquamous carcinoma (PASC), which are two rare subtypes of pancreatic cancer accounting for less than 5% [13] and 4% [14] of all pancreatic malignancies, respectively.