Circular extrachromosomal DNA regions are frequently observed in glioblastomas and contribute to development of gene mutations through a mechanism called amplification-linked extrachromosomal mutations (ALEMs), generating mutations in relevant oncogenic genes, such as EGFR and PDGFRA [6], thus leading to the development of gene amplifications [7]. The gene discussed is PDGFRA; the disease is glioblastoma.