Fig. 1

RET rearrangements visualized via fluorescence in situ hybridization (FISH). A and B present FISH-positive samples. RET rearrangements exhibit one orange/green fusion signal (indicated by a red circle), one orange signal, and one separate green signal (indicated by a yellow circle) per nucleus. C and D present FISH-negative samples. Non-rearrangements exhibit two orange/green-fused signals per nucleus. Fifty nuclei were counted. Nuclei with RET fusion genes in ≥ 15% were defined as RET rearrangement-positive