DNA FISH analysis identified hubs in multiple ecDNA+ human cancer cell lines, including COLO320-DM (MYC-amplified colorectal carcinoma), PC3 (MYC-amplified prostate cancer), HK359 (EGFR-amplified glioblastoma), and SNU16 (FGFR2- and MYC-amplified gastric cancer). Here, FGFR2 is linked to cancer.