MMP10 and neoplasm: Given the importance of BASCs in tumor initiation, and the inhibitory effect of Mmp10 loss on Kras-mediated BASC expansion in vivo, we assessed the role of Mmp10 in Kras-mediated BASC expansion and transformation in vitro. For this purpose, we utilized LSL-Kras mice, a model in which a conditional lox-stop-lox (LSL) Kras allele can be activated by Cre-mediated recombination [31].