The known data concerning immunomodulating, antimutagenic and antioxid
ant properties of N-acetylcystein (N-Ac), as well as the results of ye
t not numerous experiments on antitumor activity of N-Ac are summarize
d. The most promising seems the use of N-Ac for the prevention of smok
ing's unfavourable consequences (including oncological morbidity) as w
ell as for prophylaxis of primary multiple tumors in case of glutathio
n-dependent defects of antioxidant system function. Potentialy importa
nt are also the properties of N-Ac connected with its ability to influ
ence on some metabolic processes including glucose utilization and lip
id peroxidation.