Injections into Ntv-a; Nes-Cre; LSL-Cas9 and Gtv-a; hGFAP-Cre; LSL-Cas9 pups of either RCAS-PDGFB together with RCAS-TSG-gRNA vectors (either one of Trp53, Cdkn2a or Pten gRNAs), or a bicistronic RCAS-Cdkn2a-gRNA-PDGFB construct (Fig. 2a), resulted in a shortened tumor latency and increased total tumor incidence as compared to the co-injections of RCAS-PDGFB and RCAS-gRNA non-targeting control (Ctrl) (Fig. 2c and Supplementary Fig. 2b). The gene discussed is PDGFB; the disease is neoplasm.