KRT19 and neoplasm: Histochemical analysis revealed positive staining for both A/N+shEzh2#1, A/N+shEzh2#2 and A/N+C transfection‐induced tumour cytokeratin 19, a classical biomarker for CCA and the knockdown effects of Ezh2 were also demonstrated by histochemical staining (Figure S1A).