Spatial localization of cells was defined in the histologic context of the tissue as determined by annotations of viable tumor, necrotic tumor, and tumor stroma regions applied by a veterinary pathologist (EFE) on hematoxylin and eosin serial sections adjacent to those used for immunofluorescence of ER− breast tumors (n = 21 including 16 TNBC and five HER2-positive) from a previously reported cohort (2, 4, 17). Here, ERBB2 is linked to neoplasm.