CD33 and cancer: The morphologic differences observed in our tumoroids were further confirmed by results of quantitative polymerase chain reaction which indicated significantly higher levels of stem cell/cancer stem cell markers (e.g., Lgr5, Axin2, Cd33, Prom1/Cd133) and lower levels of the differentiation marker Muc2 in ApcMin/+ WT tumoroids as compared with ApcMin/+ Stat2−/− tumoroids.