The role of NK and NKT cells infiltration in colorectal cancer is not well understood [19], and few studies have analyzed CD56+ cells in colorectal cancer progression: they reported low levels of CD56+ cells in colorectal cancer [22], [23], and the evidence that infiltration of NK cells in malignant tumours was associated with a favourable outcome [21]. This evidence concerns the gene NCAM1 and colorectal cancer.