The results of flow cytometry, which were consistent with the results of the fluorescence microscopy assay, further confirmed that VP2 can specifically bind to CHO-K1/VPAC1 cells and several types of CRC cell lines based on high levels of fluorescence, which likely varied because of the different expression patterns of VPAC1 receptors on these cells (Figure 7). The gene discussed is VIPR1; the disease is colorectal carcinoma.