ERBB2 and colorectal carcinoma: Despite the frequent use of IHC in carcinomas of breast and stomach, IHC as well as fluorescence in situ hybridization (FISH) have not yet been completely adapted for HER2/neu amplification in CRC [13,14]. The guidelines for immunohistochemistry/fluorescence in situ hybridization interpretation in CRC are summed up in Table 1.