Foetoprotein -

Clinicians distinguish between two primary forms of this protein based on when and why it appears in the body:

A "valuable ally" in the fetal stage, responsible for stimulating essential tissue and cell growth. In healthy adults, it is mostly suppressed, existing only in trace amounts (typically <25is less than 25

A "treacherous foe" produced by certain cancers, such as hepatocellular carcinoma (HCC) and germ cell tumors. Alpha Fetoprotein (AFP) Tumor Marker Test - MedlinePlus

Alpha-fetoprotein (AFP) is a specialized glycoprotein often described as the fetal version of albumin. It is primarily produced by the during development. While it is a vital growth factor for a developing fetus, its reappearance in adulthood often signals significant medical shifts, ranging from liver regeneration to high-malignancy tumors. The Two Faces of AFP