KRAS and neoplasm: BASCs undergo expansion and transformation in response to Kras activation [29], and genetic and/or pharmacological disruption of multiple key oncogenic pathway genes involved in Kras-mediated tumorigenesis, including Prkci[30], Pik3ca[35], and Bmi1[36], lead to inhibition of BASC expansion and Kras-mediated tumor formation in vivo.