MKI67 and schwannoma: Indeed, even with low levels of Ki-67, the lesion may be avid for 18F-FDG, as there is no correlation between Ki-67 expression and 18F-FDG uptake in schwannomas (13), and this avidity for 18F-FDG could be due to overexpression of GLUT1 or GLUT3, although this is not certain as studies give different results (14, 15).