Which cells harvested from adult mice were most likely used as the highly proliferative benchmark?

Gastrointestinal epithelial cells. The epithelial cells that like the gastrointestinal tract are typically HIGHLY PROLIFERATIVE. Cells that line gastrointestinal tract. Cells proliferate and produce plasma cells. The plasma cells bear antibodies with the identical antigen specificity as the antigen receptors of the activated B cells. 

answer; i believe the correct answer is (replication is not conservative);

climate change and pollution