For example, organoid cells of patient #4 were initially cultured in the conditioned medium and tumor cells highly expressed OLFM4 whereas the normal epithelial cells highly expressed CA2. After organoid cells were transferred to a chemical-defined medium, tumor cells, and normal epithelial cells still maintained this distinct expression patterns of OLFM4 and CA2 (Fig. 5A). The gene discussed is OLFM4; the disease is neoplasm.