Among studies that investigated TNBC and PV in the BRCA gene, the biological behavior and natural history of the disease were analyzed mostly in relation to the BRCA1 gene mutation (or in BRCA1/2 carriers together), since patients with PV with the BRCA2 gene and with TNBC are a very rare occurrence.20, 21, 22, 23, 24. Here, BRCA2 is linked to acquired polycythemia vera.