Brief Research ReportPublished 15 September 2026R2Tg retrotransposon mediated targeted integration of exogenous genes into the 28S rDNA locus in mammalian cell lines for PKU gene therapyXiuyuan Wang · Ziqi Wen · Rongjun Xu · Wenjing Shi · Yiling Long · Xingri Zhan · Rui Su · Jia Fei · Yumin LiFrontiers in Genome Editingdoi 10.3389/fgeed.2026.1893815