Circadian Clock New and Updated Topics and Pathways. Topics with new or revised pathways in this release include Autophagy ( Macroautophagy ), Cell Cycle ( Cyclin A/B1/B2 associated events during G2/M transition , Regulation of PLK1 Activity at G2/M Transition ), Cellular responses to stimuli ( Heme signaling ), Chromatin organization ( ATP-dependent chromatin remodellers ), Circadian Clock , Developmental Biology ( Developmental Cell Lineages of the Exocrine Pancreas , Developmental Lineage of Multipotent Pancreatic Progenitor Cells , Developmental Lineage of Pancreatic Ductal Cells ), Diseas