The evaluation of angiogenesis with anti-CD31 antibody revealed that high microvessel counts were strongly associated with DCIS-I and DCIS-H, with a mean of 140 ± 32 and 146 ± 38 respectively and to a lesser extent with DCIS-L, ADH, FA, LCIS and ALH (mean values 121 ± 13, 119 ± 10, 114 ± 9, 111 ± 7 and 109 ± 5 respectively). Here, PECAM1 is linked to ductal breast carcinoma in situ.