To comprehensively identify mutations mediating resistance to the FDA-approved inhibitors pemigatinib (designed to target FGFR1–3) and futibatinib (designed to target FGFR1–4), we established a second pooled high-throughput system in the FGFRi-sensitive lung cancer cell line NCI-H1581. The gene discussed is FGFR1; the disease is lung cancer.