We called these models as OPCM (Organoid‐initiated Precision Cancer Model), which has been successfully used for various types of cancers, including lung cancer,[21] gastric cancer,[22] bladder cancer,[23] and endometrial carcinoma.[24] First, we cultured organoids of nasopharyngeal epithelium from CAG‐Cas9‐EGFP; Trp53‐/‐; C57BL/6 mice (Figure 2A). The gene discussed is TP53; the disease is gastric cancer.