"lacking cells; \"cell-free systems\"; \"a cell-free homogenate of the thyroid\""@en-us . . "300328270"@en-us . "300328270"^^ . . "0"^^ . . "0.25"^^ . "cell-free"@en-us . "00328270-a"^^ . . "300319846"@en-us . "300324493"@en-us . . "cell-free"^^ .