Human embryonic prealbumin as a marker for tumours and fibroblasts.

Embryonic prealbumin (E.P.A.) was demonstrated by agar immunodiffusion in 122 out of 505 homogenates of various tumours and in 7 out of 20 serum samples from patients with connective-tissue tumours. Analogous antigen was found in human embryonic and adult cultured fibroblasts. This newly identified antigen is probably actively secreted by fibroblasts into the circulation of patients with tumours.