Any process that stops, prevents, or reduces the frequency, rate or extent of signal transduction mediated by the MAPKKK cascade. [ GOC:go_curators ]
Synonyms: negative regulation of mitogen activated protein kinase cascade negative regulation of MAP kinase kinase kinase cascade downregulation of MAPKKK cascade down-regulation of MAPK cascade negative regulation of MAP kinase cascade negative regulation of MAPKKK cascade negative regulation of mitogen-activated protein kinase cascade down-regulation of MAPKKK cascade downregulation of MAPK cascade down regulation of MAPK cascade down regulation of MAPKKK cascade negative regulation of mitogen activated protein kinase kinase kinase cascade negative regulation of mitogen-activated protein kinase kinase kinase cascade