NEAA proline can be synthesized by aldehyde dehydrogenase family 18 member A1 (ALDH18A1, P5CS) and pyrroline-5-carboxylate reductase (PYCR) from glutamine and arginine, thus MYC induced P5CS and PYCR upregulation can promote the proliferation and invasion of cancer cells [28, 123]. This evidence concerns the gene PYCR1 and cancer.