TEK and anemia (phenotype): Tie2-Cre+, Baf200f/f embryos showed severe anemia and profound growth retardation as early as E15.5 compared with their WT Tie2-Cre−, Baf200f/f or Tie2-Cre−, Baf200f/+ littermates (Fig. 1a and Additional file 1: Figure S2b).