BRCA2 and neoplasm: In addition, they found a differential pattern of alterations between BRCA2 and BRCAX tumors, with TP53/PTEN alterations, gain of STK11 SMARCB1, and HRAS, loss of RB1 being more frequent in the first and PIK3CA alterations being more frequent in the latter, suggesting different tumor pathways for BRCA2 and BRCAX MBCs [25].