NAB2 and solitary fibrous tumor: The NAB2 exon 4–STAT6 exon 2–3 variant seems to be most often found in tumors resembling the conventional ‘solitary fibrous tumor,’ while tumors with NAB2 exon 6–STAT6 exon 16–17 exhibit morphologic features consistent with what was previously considered ‘hemangiopericytoma’ [1, 3, 11].