FGFR2 and neoplasm: For instance, when a commercial ctDNA assay (Guardant360) was applied to tumour tissues from 14 patients, which harboured 20 unique FGFR2/3 alterations, the assay was able to detect 4 out of 5 SNVs, 1 out of 2 amplifications and only 5 out of 13 fusions.49 Guardant360 is also being used for the identification of resistance mutations in patients being treated with FGFR inhibitors.