PKM and glioblastoma: Because work in glioblastoma has suggested that PKM2 is required for β-catenin activation downstream of EGF stimulation in that tissue [8], we determined whether loss of PKM2 impacted β-catenin localization in tumors arising in Apcflox/flox;Pkm2flox/flox mice (Fig. 3a, b, Additional file 1: Figure S1C).