Abstract
Pregnancy-specific beta-1-glycoprotein (SP1) is said to be found only in sera of pregnant females. In this paper, SP1 in the sera of malignant tumor patients was investigated by means of Ouchterlony's method and counter immunoelectrophoresis (CIEP). On the examination by Ouchterlony's method, all samples were negative, but by CIEP, 34 out of 90 samples (38%) showed positive reaction; 25 out of 61 (41%) in males and 9 out of 29 (31%) in females. There was no indication that the patients with a certain type of cancer tend to have a high incidence of SP1, but the examination of SP1 in the sera of patients with cancer or suspicious cancer had some clinical significance.