KRAS and neoplasm: Further affirming the value of slices, our results on ex vivo inhibition of KRAS effector pathways align with published preclinical data; the finding that AC slices show selective sensitivity to dact + sel combination treatment agrees with the observation that combined MAPK + PI3K–mTOR inhibition reduces the AC tumour burden of KrasG12D mice more effectively than single pathway inhibition 25.