To identify the NAB2-STAT6 fusion type of the IEC139 PDX model, total RNA was extracted from resected PDX tumor samples and subjected to RT-PCR and Sanger sequencing using primers specific to the fusion type (forward primer P18: within exon 6 of NAB2; reverse primer P19: within exon 16 of STAT6). Here, NAB2 is linked to neoplasm.