PIMREG and colorectal carcinoma: In agreement with these mechanistic findings, we have recently demonstrated that specific inhibition of CatS by an antibody, Fsn0503, could attenuate CRC cell invasion in vitro and significantly reduce colorectal xenograft tumour growth (Burden et al, 2009) Although these recent in vitro and in vivo findings suggest that CatS has an important role in CRC pathogenesis, the evaluation of its clinical significance in CRC patient samples has not been performed to date.