PHGDH-inactive is primarily utilized in research settings to study the role of its active counterpart, 3-phosphoglycerate dehydrogenase (PHGDH), in cellular metabolism. It serves as a control or reference in experiments to understand the enzyme's function in serine biosynthesis, which is crucial for cancer cell proliferation and survival. By comparing the effects of PHGDH-inactive with the active enzyme, researchers can identify specific pathways and mechanisms involved in diseases like cancer. Additionally, it aids in the development of targeted therapies by providing insights into how inhibiting PHGDH activity might disrupt tumor growth. Its use is also extended to studying metabolic disorders and exploring potential treatments by modulating serine metabolism pathways.