Traditional understanding of anti-tumor
immunity is based on the theory of immunological
surveillance and it suggests function
of cytotoxic lymphocytes that can recognize
tumor-specific antigens and lyse malignantly
transformed cells. However tumor
development is not the direct result of
immune system disorders and even in
case of marked immuno-deficiencies, in
particular, in patients – transplant recipients,
immune dysfunction does not always lead
to higher cancer incidence comparing with
total population