Objective: ETV1 has been proposed to be activated by KITmutations in gastrointestinal stromal tumors (GISTs). Aim of the study was to evaluate the role of ETV1 and associated proteins in GIST. Method: Expressions of ETV1, MAPKAP kinase 2 (MAP-KAPK2), phosphorylated p38 MAP kinase (pp38), phosphorylated MSK1, phosphorylated RSK1, COP1 and KIT were determined immunohistochemically in 139 GISTs. Sequence analysis of KIT, PDGFRA and MAPKAPK2 and FISH of ETV1 and chromosome 1 was performed.