ERAS and breast neoplasm: In addition, immunohistochemical and microarray expression analyses have revealed that ERAS is expressed in up to 45% of gastric carcinomas and in their liver metastasis [16,17,18] and in a lower percentage of breast tumors [12], although it is not known if this expression is relevant in tumorigenesis or simply a secondary effect of gene expression deregulation associated to tumor development.