To bridge this gap, we delivered the ETV6::NTRK3 fusion gene alone or in combination with a sgRNA targeting Trp53, which led to tumors with 100% penetrance in both P30 and P0 animals, with a moderately higher efficiency in P30 mice (45 days versus 52 of mean latency, 100% versus 0% bilateral tumor fraction). The gene discussed is ETV6; the disease is neoplasm.