BUB1B and pancreatic ductal adenocarcinoma: On the other hand, studies have shown that overexpression of BUB1/BUB1B is related to progression and recurrence of various tumors including glioblastoma [29], pancreatic ductal adenocarcinoma [31–33], prostate cancer [34], gastric adenocarcinoma [35], and hepatocellular carcinoma [36].