Beschreibung:
<jats:title>Abstract</jats:title><jats:p>A biological activity which enhances cell transformation (TEF) in Rous sarcoma virus temperature‐sensitive mutant‐infected cultures has been evidenced in the plasma cryoprecipitate from patients affected with different types of neoplastic disease. In the present paper we report data on the analysis of TEF activity in the plasma cryoprecipitates from leukemic and tumor patients tested either before or during specific antineoplastic treatments. The screening of 57 cases of different neoplastic diseases and of 57 controls, healthy subjects or patients affected with other non‐neoplastic diseases indicates that TEF activity is generally related to the presence of neoplasia. Furthermore, a follow‐up of patients from the onset of the disease through its evolution during therapy suggests that variations of TEF activity in the plasma cryoprecipitate correlate well with the clinical and pathological conditions, thus indicating the TEF as a potential marker for monitoring cancer patients.</jats:p>