We also analyzed the expression patterns of other signature genes in organoid cells of these two patients and showed that normal tissue-derived organoid cells highly expressed REG4 and SPINK4, while tumor tissue-derived organoid cells highly expressed DPEP1. Similar to previous results, both normal tissue-derived organoids and tumor tissue-derived organoids highly expressed in vivo tumor-specific marker gene CEACAM6 (Fig. 5C and E). This evidence concerns the gene REG4 and neoplasm.