With respect to grade of differentiation in CRC cases, 4/6 of the positive and equivocal tumors were of low grade and exhibit mainly strong cytoplasmic/membranous expression, however no significant relationship was observed between CRC grades and HER2 pattern, which is consistent with several studies (Elwy et al., 2012; Pappas et al., 2013; Sayadnejad et al., 2017). This evidence concerns the gene ERBB2 and colorectal carcinoma.