In contrast, progression of tumors produced by TIM-barrel-transfected cells appeared comparable with control mock transfected cells.67 These results show that in some tumor systems (i.e. glioma) heparanase facilitates primary tumor progression regardless of its enzymatic activity, while in others (i.e. myeloma) heparanase enzymatic activity dominates (see below). This evidence concerns the gene HPSE and central nervous system cancer.