KRAS and lung carcinoma: Having established the approach in normal tissues, we next performed chromatin tracing on the K-MADM-Trp53 mouse lung cancer model (Fig. 1a and Extended Data Fig. 1g,h) that induces sparse and sequential Kras and Trp53 mutations in the lung epithelium to mimic the faithful genetic and histologic progression of human LUAD25–27.