passages.id: split_6_test_1259_passage
passages.type: progene_text
passages.text: Screening at low stringency with a gp91 ( Phox ) probe of cDNA libraries from thyroid cells in primary culture yielded two distinct human cDNA clones harboring open reading frames of 1551 ( ThOX1 ) and 1548 amino acids ( ThOX2 ) , respectively .