lose weight on tamoxifen The lineage tracing data presented here lead us to conclude that 1 the lineage tracing system was highly specific for ОІ cells in mice of the genetic constitution we employed; 2 there was a dilution of the labeling index associated with pregnancy; 3 although not statistically significant, pregnancy was associated with the appearance of more small islet sections that were unlabelled by HPAP; and 4 there was no transdifferentiation of ОІ cells to other cell types, either within islets or in exocrine tissue, up to 2