MUC4 and cancer: Among the top 27 mutated genes in organoids and the corresponding tissues (Figure 2D), we identified variations in cancer‐associated genes, including TP53, MUC4, MUC16, CTNNA2, TTN, RYR2, MGAT5B, USP29 and AKAP6 in GBC organoids and CTNNA2, CTNNB1, KCNIP3 and DSCAML1 in GBA organoids.