TGFBR1 and neoplasm: Similar findings were seen in tumours originating from the hair follicle stem cells upon MAPK signalling hyperactivation and deletion of the TGFβ receptor 1 (Alk5) (Lgr5:BRAFV600E-ALK5fl/fl, Lgr5:HRASG12V/G12V-ALK5fl/fl, Lgr5:KRASG12D/+-ALK5fl/fl)14 and deletion of Trp53 and Notch2 (Lgr5:TRP53fl/fl-NOTCH2fl/fl) (Supplementary Fig. 6b).