Cejalvo et al. [33] compared the analysis of intrinsic subtypes, according to PAM50 assay, from primary tumor vs. metastasis in 123 tissue samples from pts with ABC: the study demonstrated high concordance between the two tissue types for LumB, HER2E, and basal-like; on the contrary, for LumA it was observed that 40.4% became LumB and 14.9% became HER2E. The gene discussed is TMEM43; the disease is neoplasm.