PAX6 and pancreatic neoplasm: PANC-1 CSC pancreatic cancer spheroids also expressed PAX6, a transcription factor involved in pancreatic cancer and the maintenance of stem cells [57,58,59], and pancreatic and duodenal homeobox 1 (PDX1), also known as insulin promoter factor 1 (IPF1), a key transcription factor in pancreatic embryogenesis and pancreatic cell differentiation [60,61], as assessed by confocal microscopy (Figure 2d).