Moreover, in the myenteric/submucous plexuses, a decrease in the number of NPY-immunoreactive neurons/nerve fibers was observed in colorectal tumor samples [122], and the absence of perivascular nerves into the tumors and the loss of perivascular innervation in the submucosa placed close to the tumors have been reported in colorectal cancer [123]. This evidence concerns the gene NPY and colorectal cancer.