Nearly one-third of lesions with internal grade differences demonstrated further diversity for a panel of immunohistochemistry markers including ER, GATA-binding protein 3 (GATA3), and HER2.31 The authors concluded that higher-grade DCIS gradually evolve from lower-grade in situ lesions by random accumulation of genetic mutations. The gene discussed is GATA3; the disease is ductal breast carcinoma in situ.