Transcription FactorsHumansHSP90B2PHeartVisceraLarvalineageLeftyCerberusexpressionPitxfeedbackvertebrateamphioxusasymmetryleft-rightleft-right asymmetryright sidephenotypicembryoleft-sidedoverexpressionanimal showmirror-image symmetryfeedback loopNoda lsignal geneasymmetric expressionasymmetric expression of the signal geneextraordinary asymmetryclose relative of vertebrateembryo of amphioxusplacement of the heartprogrammed differencesymmetrical animal show