To verify the functional role of PYCR1 in lung cancer, we generated PYCR1-knockout (PYCR1-KO) human lung cancer cells using CRISPR–CRISPR-associated protein 9 (Cas9) gene editing to assess the impact of PYCR1 loss on cell proliferation, migration and tumor formation in both in vitro and in vivo. The gene discussed is PYCR1; the disease is lung cancer.