 The study investigates the role of extra chromosomal DNA, ectdna, in the development of intratumagenetic heterogeneity, IgH, in CISPR-Cas9-induced mouse liver cancer. The results show that ectdna's carrying targeted TSG mutations may serve as an important source supporting IgH and tumor evolution in these liver tumors, even after the cessation of CISPR-Cas9 genome editing. This article was authored by Daogua, Guaciao Chen, Chufan Li, and others.