CTSS and gastric cancer: Zhang et al. (2008) published a proof of principle trial of the biochromoendoscopy technique, in which VCE was able to discriminate between adenomas and benign lesions by detecting the NIRF signal released from a cathepsin-B activated probe. The same cathepsin-activated probe was able to spotlight adenocarcinomas in a gastric cancer murine model. (Ding et al., 2012).