Mammary carcinomas of F1 HER2/Delta16 mice presented both types of vascularization (Supplementary Figure 2), however, when we classified the tumors by the prevalent HER2 isoform expressed (see Figure 2A), we found that tumors with high full-length HER2 expression showed few large vessels (Figure 3E and 3F), whereas tumors with low full-length HER2 and high Delta16 mainly contained numerous small vessels (Figure 3I and 3J). The gene discussed is ERBB2; the disease is breast carcinoma.