RET and central nervous system cancer: To better estimate differences in the growth kinetics of Pdgfbret/ret and Pdgfbret/+ mice, we fit the data to a non-linear model and observed a higher glioma growth rate in Pdgfbret/ret mice over time (Figs. 2J and S3), indicating a growth advantage over Pdgfbret/+ gliomas, in keeping with their higher proliferative rate and faster induction of end-stage disease.