In 2013, Buza et al. reported that among USC samples, IHC and FISH concordance was 75–81% depending on which scoring criteria were used [15]; as these both fell below the recommended concordance of 95% described in ASCO/CAP guidelines for HER2 scoring of breast cancer, the authors argued for standardized IHC and FISH testing on all USC cases until testing concordance improves [16]. Here, ERBB2 is linked to breast carcinoma.