many transformed and malignant cells , unlike normal cells , do not grow when methionine in the growth medium is replaced by its immediate precursor homocysteine [ chello , p. & bertino , j . ( 1973 ) cancer res . 33 , 1898-1904 and hoffman , r. & erbe , r. ( 1976 ) proc . natl . acad . sci . usa 73 , 1523-1527 ] .
C0334227
malignant cells
C0006826
cancer