cell lines that produce only free alpha subunit in culture ( hela cervical carcinoma , chago bronchogenic carcinoma , and bt-20 breast carcinoma ) continue to produce primarily free alpha subunit in vivo , but a small amount of hcg-beta/hcg is detectable in the 24-hr urine collected from mice bearing hela or chago tumors .
C0017963
alpha subunit
C0018062
hcg