Rare Fusions, Real Targets: Ultraprecision Oncology in Lung Cancer.

Beyond established rare fusions, such as ALK and ROS1, emerging ultrarare fusions involving receptor tyrosine kinases or their ligands, including EGFR-SHC1, further guide us to uncover novel mechanisms of oncogenic activation and corresponding treatment strategies. Collectively, rare and ultrarare genomic events are driving precision oncology toward an increasingly individualized era of "ultraprecision" cancer therapy. See related article by Zheng et al., p. 1573.