MAPK3 and neoplasm: Furthermore, to evaluate whether the cGAMP-induced tumour EC apoptosis is mediated directly through STING activation in tumour ECs, we generated an inducible, endothelial cell-specific STING-deleted mice (STINGiΔEC) by crossing STINGfl/fl mice with VE-cadherin-Cre-ERT2 mice36 (Supplementary Fig 2a).