On the other hand, the observation of increased glioblastoma cell death in cells transfected with parvovirus H-1 showing an accumulation of cathepsins B and L in the cytosol or reduced levels of cystatin B and C, suggests pro-apoptotic function of cysteine cathepsins also in tumor cells (Di Piazza et al., 2007). Here, CTSB is linked to neoplasm.