passages.id: split_5_test_2425_passage
passages.type: progene_text
passages.text: In this study , we compared the activities of mutant RET - MEN2A with substitutions of each of nine tyrosines for phenylalanine ( Y1062F , Y1015F , Y981F , Y952F , Y928F , Y905F , Y900F , Y864F , and Y826F ) , which had been transfected into NIH 3T3 cells .