“…In the spleen, CD8 levels, as estimated by tumor antigen specific activity, were unchanged following radiotherapy alone and usually increased in combination with an immunostimulant ( 157 , 161 , 182 , 191 , 200 ). Radiotherapy alone did not usually affect tissue levels of CD8 in untreated tumors ( 160 , 161 , 172 , 176 , 195 , 196 , 198 – 200 , 214 , 215 ) but both an increase and a decrease have been reported ( 173 , 174 , 190 , 197 ). Combination with immunotherapy, regardless of the type, always increased CD8 levels in untreated tumors in these studies.…”