The Western blot results revealed that the changes in the expression of cell cycle‐related proteins, apoptosis‐related proteins and tumour metastasis‐related proteins were abolished after IRS1 was overexpressed in PYCR1‐knockout or PYCR1‐inhibited LC cells (Figure 6E). The gene discussed is PYCR1; the disease is laryngotracheoesophageal cleft.