(A) DNA sequence of clone 3R30. The end of ETV6 exon 2 shown in capitals and the sequence with partial homology to a region upstream of the mouse CDX2 gene is underlined. (B) Amino acid and mRNA sequences of normal ETV6, normal CDX2 and the smaller ETV6-CDX2 product at the site of fusion. (C) Sequence of larger ETV6-CDX2 fragment. The end of ETV6 exon 2 and the start of CDX2 exon 2 are shown in capitals. The stop (TAA) and potential start (ATG) codons referred to in the text are shown underlined.