These decreases were not significantly different from the hypothesis of random change (sign test, P = 1.00 and P = 0.77, respectively), nor was the mean percentage of Ki67-positive cells significantly different in core versus excision biopsies (1.1 ± 5.2%, WSR P = 0.44 for AH and -0.6 ± 16.1%, WSR P = 0.97 for DCIS), (Figure 3C-D). The gene discussed is MKI67; the disease is ductal breast carcinoma in situ.