To exclude the possibility that the anemia and premature death phenotype in Bmp10-iKO and Bmp9/10-dKO mice are related to the direct hematological toxicity caused by the systemic activation of R26CreER/+, we compared the complete blood counts in neonatal R26CreER/+;Bmp10+/+ and their littermate controls (R26+/+;Bmp10+/+ or R26+/+;Bmp102f/+) after treatment with the same tamoxifen regimen (Fig. S5a). Here, BMP10 is linked to anemia.