A) The ECM protein EFEMP2, but not SPARC, inhibited activin-induced mesodermal formation in animal caps. B) EFEMP2 interfered with mesodermal induction by both activin and the activated type I activin receptor ALK4 (CA-ALK4), but did not inhibit mesodermal induction by Smad2 or Smad2-induced animal cap elongation. The doses of RNA used: activin, 2pg; CA-ALK4, 1ng; Smad2, 1ng; EFEMP2, 1ng.