CGB1 encodes a chorionic gonadotropin beta subunit and is part of a gene cluster on chromosome 19.32 that produces human chorionic gonadotropin (hCG), a hormone with roles in pregnancy and placental function 1. Originally classified as a pseudogene, CGB1 is transcriptionally active 2, with evolutionary analysis suggesting it originated recently in humans and African great apes through frameshifting, potentially encoding a novel protein distinct from canonical hCG beta subunits 3. CGB1 expression is detected in normal pregnancy tissues, with particularly high expression in testis relative to other non-reproductive tissues, suggesting a possible role in male reproduction 4. Clinically, CGB1 transcripts are aberrantly activated in multiple cancer types, including ovarian, breast, bladder, cervical, esophageal, and lung cancers 1. In cancer cells secreting ectopic hCG-beta, CGB1 silencing significantly reduces both protein secretion and cell survival, indicating functional importance beyond its pseudogene classification 5. CGB1 expression correlates with aggressive tumor phenotypes and metastatic potential, positioning it as both a potential cancer biomarker and therapeutic target 5. However, the precise protein product and molecular mechanisms remain to be fully characterized.