Antral organoids of Mist1-CreERT; Apcflox/flox mice can grow without Wnt3a and R-spondin 1 in culture media only when recombination is induced by tamoxifen, suggesting that the tumor development in these mice is cell-autonomous effect (Supplementary Figure 3E, 3F). The gene discussed is RSPO1; the disease is neoplasm.