DNMT1 and exocrine pancreatic carcinoma: In PANC-1 cells, an epithelial-like cell line derived from a human pancreatic carcinoma, a clear 24 h periodicity was observed for the time qualified variations of PPARG and DNMT1 expression, a borderline significant rhythmicity with a 24 h period was observed for the DNMT3B expression pattern, and the time qualified profiles of PPARG and DNMT3B were opposing, whereas those of PPARG and DNMT1 were different, and the time qualified profiles of DNMT1 and DNMT3B showed flat shapes.